A Cu/Pd Cooperative Catalysis for Enantioselective Allylboration of Alkenes Tao Jia, Peng Cao, Bing Wang, Yazhou Lou, Xuemei Yin, Min Wang and Jian Liao* Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China; jliao@cib.ac.cn S1
General Procedures All reactions were generally performed in dried glassware under an atmosphere of dry Ar. Reaction mixtures were stirred magnetically unless otherwise indicated and monitored by thin layer chromatography (TLC) with visualization by fluorescence quenching at 254 nm. TLC plates were stained using potassium permanganate or I 2. Chromatographic purification of products (flash column chromatography) was performed on the glass column filled in (300 400 Mesh) silica gel. Concentration of reaction product solutions and chromatography fractions under reduced pressure was performed by rotary evaporation at 30-35 C at the appropriate pressure and then at rt, ca. 0.1 mmhg (vacuum pump) unless otherwise indicated. Materials All commercially available reagents were used as received without further purification. Solvents used in the catalysis were distilled from appropriate drying agents. 2a 2f, 2i 2k, 2m, 2n, 2q and 2r were purchased from Alfa Aesar. 2g 1, 2h 2, 2l 3 and 2p 4 were prepared according literature. Allylic Carbonates were prepared following literature precedence 5. KOH, Diboron pinacol ester and PdCl 2 (dppf) were purchased from Alfa Aesar, used as received. A, E, F, G, H and L1-L6 were synthesized according to the literatures. 6 B, C, D and L7 were purchased from Daicel Chiral Technologies Co., LTD. Instrumentation NMR spectra were recorded on a Bruker 400 spectrometer operating at 400 MHz for 1 H NMR and 100 MHz for 13 C NMR. Chemical shifts were reported in ppm relative to the central line of CHCl 3 (δ 7.28) for 1 H NMR, for 13 C NMR, the residual CDCl 3 (δ 77.2) were used as the internal standards. The coupling constants are in Hertz (Hz). The following abbreviations are used for spin multiplicity: s = singlet, d = doublet, dd = doublet of doublet, dq = doublet of quartet, t = triplet, m = multiplet and brs = broad singlet. Optical rotation was recorded on PE polarmeter 341. Enantiomeric excess was determined by HPLC analysis on Chiralpak OJ, OD, AD, AS column (Daicel Chemical Industries, LTD). Electrospray ionization high-resolution mass spectra (ESI-HRMS) were recorded on a Bruke P-SIMS-Gly FT-ICR mass spectrometer. Preparation of allylic carbonates 5 S2
Vinylmagnesium bromide (1 equiv., 1 M/L in THF) was added to a solution of the corresponding aldehyde in THF at 0 C. After 15 min the reaction was allowed to warm to RT and stirred for additional 1-3 h. The reaction mixture was quenched by addition of saturated aqueous NH 4 Cl and extracted with Et 2 O. The organic phase was washed with brine, dried over MgSO 4. The solvent was removed in vacuum and the residue was purified by column chromatography (6:1 petroleum ether/ethyl acetate) to provide the allylic alcohol as a colorless oil. To a flame-dried round-bottomed flask with stir bar was added allylic alcohol and dried THF. The solution was cooled to -78 C and butyllithium (1 equiv., 2.5 M/L in hexane) was added, dropwise. The solution was stirred for 30 minutes at -78 C, Boc 2 O (1 equiv.) in 4 ml THF was added. The reaction was allowed to warm to room temperature, stirring overnight. The reaction mixture was diluted with 10 ml of diethyl ether and 7 ml of water, and the mixture was stirred 15 minutes. The organic layer was separated and the aqueous layer was extracted with diethyl ether (15 ml X 3). Combined organics were washed with brine then dried over MgSO 4, filtered, then concentrated in vacuo. The crude reaction mixture was purified by column chromatography (50:1 petroleum ether/ethyl acetate) to afford a colorless oil. tert-butyl penta-1,4-dien-3-yl carbonate (2f) Colorless oil, 71% yield. 1 H NMR (400 MHz, CDCl 3 ) δ 5.92 5.83 (m, 2H), 5.48 (t, J = 6.2 Hz, 1H), 5.36 (d, J = 17.2 Hz, 2H), 5.27 (d, J = 10.4 Hz, 2H), 1.50 (s, 9H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 152.6, 134.9, 117.7, 82.2, 78.1, 27.8 ppm. tert-butyl (1-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)allyl) carbonate (2g) Colorless oil, 90% yield. 1 H NMR (400 MHz, CDCl 3 ) δ 5.90 5.74 (m, 1H), 5.44 5.30 (m, 2H), 5.10 5.06 (m, 1H), 4.24 4.17 (m, 1H), 4.06 3.97 (m, 1H), 3.88 3.77 (m, 1H), 1.48 (s, 9H), 1.42 (s, 3H), 1.35 (s, 3H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 152.7, 132.5, 119.1, 110.0, 82.4, 77.9, 76.5, 65.9, 27.7, 26.4, 25.3 ppm. S3
Optimization Studies for Asymmetric Allylboration of the Styrene a Entry LG Ligand CuX Base Solvent Yield b (%) (3aa/4+5) Ee c 1 Br dppf CuCl NaOtBu MTBE No reaction / 2 OAc dppf CuCl NaOtBu MTBE 30%/19% 86% 3 OCOMe dppf CuCl NaOtBu MTBE 32%/31% 89% 4 OBoc dppf CuCl NaOtBu MTBE 39%/19% 90% 5 OCOEt dppf CuCl NaOtBu MTBE 35%/28% 89% 6 OBoc XanPhos CuCl NaOtBu MTBE 22%/21% 89% 7 OBoc BINAP CuCl NaOtBu MTBE 38%/17% 90% 8 OBoc RuPhos CuCl NaOtBu MTBE trace / 9 OBoc dppf CuBr NaOtBu MTBE 25%/14% 88% 10 OBoc dppf CuI NaOtBu MTBE 25%/5% 81% 11 OBoc dppf CuOAc NaOtBu MTBE 65%/21% 84% 12 OBoc dppf CuOTf NaOtBu MTBE 46%/16% 84% 13 OBoc dppf CuCl 2 NaOtBu MTBE 30%/17% 84% 14 OBoc dppf Cu(OAc) 2 NaOtBu MTBE 40%/32% 77% 15 OBoc dppf CuOAc KOMe MTBE 55%/29% 90% 16 OBoc dppf CuOAc KOH MTBE 62%/27% 89% 17 OBoc dppf CuOAc CsOH H 2 O MTBE 40%/30% 90% 18 OBoc dppf CuOAc K 2 CO 3 MTBE 61%/29% 89% 19 OBoc dppf CuOAc KOH THF 11%/21% / 20 OBoc dppf CuOAc KOH Toluene 15%/45% 87% 21 OBoc dppf CuOAc KOH Dioxane 38%/20% 86% a The reaction was performed with 1 (0.2 mmol), 2 (0.3 mmol), B 2 (pin) 2 (0.3 mmol), PdCl 2 (ligand) (5 mol %), the copper salt (10 mol %), A (12 mol %), the base (0.2 mmol) in t BuOMe (4 ml) at 20 o C for 12h S4
b Determined by 1 H NMR spectroscopy. c Determined by HPLC analysis. a The reaction was performed with 1 (0.2 mmol), 2 (0.3 mmol), B 2 (pin) 2 (0.3 mmol), PdCl 2 (dppf) (5 mol %), the Cu(OAc) (10 mol %), chiral L (12 mol %), KOH (0.2 mmol) in t BuOMe (4 ml) at 20 o C for 12h b Determined by 1 H NMR spectroscopy. c Determined by HPLC analysis. General procedure of enantioselective Allylboration of the Styrene In the glove box, to a flame-dried tube was added CuOAc (2.4 mg, 0.02 mmol), H (8.6 mg 0.024 mmol) and 1.0 ml of dried t-buome. The solution was stirred for 30 min, followed by the addition of (Bpin) 2 (76 mg, 0.3 mmol), styrene (20.8 mg, 0.2 mmol), KOH (11.2 mg, 0.2 mmol), S5
Pd(dppf)Cl 2 (7.3 mg, 0.01mmol) and 3.0 ml t-buome. The tube was taken out of the glove box and cooled to 0 o C. Then, allyl Boc (47.4 mg, 0.3 mmol) was added and the mixture was stirred at 0 o C for 12h. 2-methylnaphthalene (14.2 mg, 0.1 mmol) was added before the reaction was filtered through celite and concentrated. The residue was monitored by 1 H NMR for conversion analysis and then purified by fast column chromatography with Petro ether/acetate (50/1) as the eluent to get colorless oil (3). The pure sample was directly characterized by 1 H NMR, 13 C NMR and HRMS, and then oxidized by NaBO 3 4H 2 O for chiral HPLC analysis. Characteristics of ennatioenriched -allylboronic esters (S)-4,4,5,5-tetramethyl-2-(2-phenylpent-4-en-1-yl)-1,3,2-dioxaborolane (3aa) O B O A colorless oil (43.5 mg, 80% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.30 7.15 (m, 5H), 5.75 5.65 (m, 1H), 5.00 4.93 (m, 2H), 3.00 2.93 (m, 1H), 2.42 2.33 (m, 2H), 1.29 (dd, J = 15.4, 6.9 Hz, 1H), 1.16 1.12 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 146.8, 137.2, 128.1, 127.4, 125.9, 116.0, 83.0, 43.8, 41.4, 24.7, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 25 BO 2 [M+Na]: 295.1840, found: 295.1837. [α] D 20 = -7.1 (c = 0.65, CHCl 3 ). (S)-2-phenylpent-4-en-1-ol 1 H NMR (400 MHz, CDCl 3 ) δ 7.38 7.24 (m, 5H), 5.80 5.70 (m, 1H), 5.08 4.98 (m, 2H), 3.86 3.75 (m, 2H), 2.95 2.88 (m, 1H), 2.55 2.39 (m, 2H), 1.36 (brs, 1H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 141.9, 136.3, 128.7, 128.0, 126.9, 116.4, 67.0, 48.2, 36.6 ppm. HRMS (m/z, ESI): Calcd. for C 11 H 14 O [M+Na]: 185.0937, found: 185.0947. [α] 20 D = +21.4 (c = 1.11, CHCl 3 ). HPLC analysis: 95% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 27.1 min and t R2 : 32.0 min). (S)-4,4,5,5-tetramethyl-2-(2-(o-tolyl)pent-4-en-1-yl)-1,3,2-dioxaborolane (3ba) S6
O B O A colorless oil (52.1 mg, 91% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.23 (d, J = 7.6 Hz, 1H), 7.18 7.14 (m, 1H), 7.11 7.03 (m, 2H), 5.76 5.66 (m, 1H), 5.01 4.93 (m, 2H), 3.29 3.22 (m, 1H), 2.38 (s, 3H), 2.37 2.26 (m, 2H), 1.28 (dd, J = 15.4, 6.4 Hz, 1H), 1.17 (dd, J = 15.3, 9.6 Hz, 1H), 1.07 (s, 6H), 1.05 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.0, 137.2, 135.6, 129.9, 126.0, 126.0, 125.5, 116.0, 83.0, 43.7, 35.9, 24.6, 20.1 ppm. HRMS (m/z, ESI): Calcd. for C 18 H 27 BO 2 [M+Na]: 309.1996, found: 309.1991. [α] 20 D = -1.1 (c = 1.06, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 97% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 13.8 min and t R2 : 18.4 min). (S)-2-(2-(2-chlorophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ca) A colorless oil (50.2 mg, 82% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.34 (d, J = 7.8 Hz, 1H), 7.28 7.27 (m, 1H), 7.22 (t, J = 7.1 Hz, 1H), 7.12 7.08 (m, 1H), 5.78 5.67 (m, 1H), 5.00 4.95 (m, 2H), 3.63 3.55 (m, 1H), 2.45 2.29 (m, 2H), 1.30 (dd, J = 15.9, 7.0 Hz, 1H), 1.19 (dd, J = 15.7, 8.9 Hz, 1H), 1.13 (s, 6H), 1.09 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 143.9, 136.5, 133.9, 129.3, 128.0, 126.9, 126.7, 116.4, 83.0, 42.4, 36.6, 24.6, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BClO 2 [M+Na]: 329.1450, found: 329.1453. [α] 20 D = -13.4 (c = 1.12, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 15.7 min and t R2 : 17.9 min). (S)-2-(2-(2-bromophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3da) A colorless oil (47.6 mg, 68% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.53 (d, J = 7.9 S7
Hz, 1H), 7.27 (d, J = 4.1 Hz, 2H), 7.04 7.00 (m, 1H), 5.79 5.69 (m, 1H), 5.00 4.95 (m, 2H), 3.60 3.52 (m, 1H), 2.46 2.38 (m, 1H), 2.35 2.27 (m, 1H), 1.27 (dd, J = 15.5, 7.0 Hz, 1H), 1.19 (dd, J = 15.5, 9.0 Hz, 1H), 1.12 (s, 6H), 1.09 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.5, 136.4, 132.6, 128.1, 127.3, 127.3, 124.9, 116.5, 83.0, 42.5, 39.3, 24.7, 24.5 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BBrO 2 [M+H]: 351.1125, found: 351.1129. [α] 20 D = -7.3 (c = 0.66, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 17.7 min and t R2 : 21.3 min). (S)-4,4,5,5-tetramethyl-2-(2-(p-tolyl)pent-4-en-1-yl)-1,3,2-dioxaborolane (3ea) A colorless oil (30.3 mg, 53% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.13 7.07 (m, 4H), 5.75 5.65 (m, 1H), 5.00 4.93 (m, 2H), 2.97 2.90 (m, 1H), 2.41 2.32 (m, 5H), 1.27 (dd, J = 15.4, 7.1 Hz, 1H), 1.14 1.09 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 143.8, 137.3, 135.2, 128.7, 127.2, 115.9, 83.0, 43.7, 40.9, 24.7, 24.7, 21.0 ppm. HRMS (m/z, ESI): Calcd. for C 18 H 27 BO 2 [M+Na]: 309.1996, found: 309.2000. [α] 20 D = -10.0 (c = 0.72, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 91% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 18.0 min and t R2 : 21.1 min). (S)-2-(2-(4-(tert-butyl)phenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3fa) A colorless oil (35.4 mg, 54% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.30 (d, J = 8.2 Hz, 2H), 7.17 (d, J = 8.3 Hz, 2H), 5.78 5.68 (m, 1H), 5.03 4.94 (m, 2H), 2.97 2.89 (m, 1H), 2.45 2.30 (m, 2H), 1.31 (s, 9H), 1.28 (dd, J = 15.3, 7.1 Hz, 1H), 1.13 1.07 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 148.6, 143.7, 137.4, 127.0, 124.9, 115.9, 82.9, 43.7, 40.9, 34.3, 31.4, 24.7, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 21 H 33 BO 2 [M+Na]: 351.2466, found: 351.2470. [α] 20 D = -11.9 (c = 0.82, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL S8
AD, eluent, hexane/2-propanol = 99/1, flow rate 0.5mL/min, detection 220 nm, t R1 : 26.8 min and t R2 : 29.2 min). (S)-2-(2-([1,1'-biphenyl]-4-yl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ga) A white solid (52.9 mg, 76% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.63 (dd, J = 8.4, 1.2 Hz, 2H), 7.56 (d, J = 8.2 Hz, 2H), 7.47 (t, J =7.4 Hz, 2H), 7.37 7.31 (m, 3H), 5.82 5.71 (m, 1H), 5.06 4.98 (m, 2H), 3.08 3.00 (m, 1H), 2.51 2.37 (m, 2H), 1.33 (dd, J = 15.6, 7.0 Hz, 1H), 1.22 (dd, J = 15.4, 9.0 Hz, 1H), 1.15 (s, 12H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 146.0, 141.3, 138.7, 137.1, 128.7, 127.9, 127.0, 126.9, 126.8, 116.2, 83.0, 43.7, 41.1, 24.7, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 23 H 29 BO 2 [M+Na]: 371.2153, found: 371.2157. [α] 20 D = -23.3 (c = 1.07, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 51.7 min and t R2 : 57.1 min). (S)-4-(1-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pent-4-en-2-yl)phenyl benzoate (3ha) A colorless oil (48.6 mg, 62% yield) was isolated by column chromatography (30:1 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 8.23 (d, J = 7.5 Hz, 2H), 7.65 (t, J = 7.4 Hz, 1H), 7.53 (t, J = 7.8 Hz, 2H), 7.29 (d, J = 8.5 Hz, 2H), 7.15 (d, J = 8.4 Hz, 2H), 5.77 5.67 (m, 1H), 5.02 4.96 (m, 2H), 3.05 2.97 (m, 1H), 2.43 2.35 (m, 2H), 1.31 (dd, J = 15.6, 6.8 Hz, 1H), 1.18 1.12 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 165.2, 149.0, 144.4, 137.0, 133.5, 130.1, 129.8, 128.5, 128.4, 121.2, 116.2, 83.1, 43.8, 40.9, 24.7, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 24 H 29 BO 4 [M+Na]: 415.2051, found: 415.2055. [α] 20 D = -12.9 (c = 1.82, CHCl 3 ). HPLC analysis directly (no oxidization): 96% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 99/1, flow rate 0.5 ml/min, detection 254 nm, t R1 : 12.7 min and t R2 : 14.0 min). (S)-2-(2-(4-fluorophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ia) S9
O B O F A colorless oil (46.4 mg, 80% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.19 7.16 (m, 2H), 6.96 (t, J = 8.8 Hz, 2H), 5.70 5.62 (m, 1H), 4.98 4.93 (m, 2H), 2.98 2.91 (m, 1H), 2.34 (t, J = 7.1 Hz, 2H), 1.27 (dd, J = 15.2, 6.5 Hz, 1H), 1.12 1.06 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 162.4 (d, J = 241.6 Hz), 142.4 (d, J = 3.2 Hz), 136.9, 128.8 (d, J = 7.7 Hz), 116.2, 114.8 (d, J = 21.0 Hz), 83.0, 43.9, 40.7, 24.7, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BFO 2 [M+Na]: 313.1746, found: 313.1740. [α] 20 D = -8.3 (c = 0.52, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 27.4 min and t R2 : 28.7 min). (S)-2-(2-(4-chlorophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ja) A colorless oil (37.3 mg, 61% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.25 (d, J = 8.4 Hz, 2H), 7.16 (d, J = 8.4 Hz, 2H), 5.71 5.61 (m, 1H), 4.98 4.93 (m, 2H), 2.98 2.90 (m, 1H), 2.34 (t, J = 7.1 Hz, 2H), 1.26 (dd, J = 15.5, 6.7 Hz, 1H), 1.13 1.06 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.3, 136.7, 131.4, 128.8, 128.2, 116.4, 83.1, 43.6, 40.8, 24.7, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BClO 2 [M+Na]: 329.1450, found: 329.1450. [α] 20 D = -15.6 (c = 0.69, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 29.8 min and t R2 : 31.6 min). (S)-2-(2-(4-bromophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ka) A colorless oil (30.1 mg, 43% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.40 (d, J = 8.4 S10
Hz, 2H), 7.11 (d, J = 8.3 Hz, 2H), 5.71 5.62 (m, 1H), 4.98 4.93 (m, 2H), 2.97 2.89 (m, 1H), 2.34 (t, J = 7.1 Hz, 2H), 1.26 (dd, J = 15.5, 6.7 Hz, 1H), 1.14 1.06 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.8, 136.7, 131.1, 129.3, 119.5, 116.4, 83.1, 43.5, 40.9, 24.7, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BBrO 2 [M+Na]: 373.0945, found: 373.0945. [α] 20 D = -16.5 (c = 0.43, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 32.8 min and t R2 : 35.1 min). (S)-4,4,5,5-tetramethyl-2-(2-(4-(trifluoromethyl)phenyl)pent-4-en-1-yl)-1,3,2-dioxaborolane (3la) A colorless oil (34.7 mg, 51% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.55 (d, J = 8.1 Hz, 2H), 7.34 (d, J = 8.1 Hz, 2H), 5.71 5.61 (m, 1H), 5.00 4.95 (m, 2H), 3.07 2.99 (m, 1H), 2.38 (t, J = 7.2 Hz, 2H), 1.31 1.24 (m, 2H), 1.13 (s, 6H), 1.11 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 150.9, 136.4, 127.8, 125.1 (q, J = 3.7 Hz), 116.6, 83.1, 43.3, 41.3, 24.7, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 18 H 24 BF 3 O 2 [M+Na]: 363.1714, found: 363.1713. [α] 20 D = -8.9 (c = 0.18, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 82% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 98/2, flow rate 0.5 ml/min, detection 220 nm, t R1 : 27.9 min and t R2 : 31.5 min). (S)-2-(2-(3-chlorophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ma) A colorless oil (44.7 mg, 73% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.22 7.09 (m, 4H), 5.73 5.62 (m, 1H), 5.00 4.95 (m, 2H), 2.98 2.90 (m, 1H), 2.42 2.30 (m, 2H), 1.28 (dd, J = 15.6, 6.5 Hz, 1H), 1.14 (s, 6H), 1.13 (s, 6H), 1.10 (dd, J = 15.6, 8.9 Hz, 1H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 148.9, 136.6, 133.8, 129.4, 127.8, 126.0, 125.6, 116.4, 83.1, 43.3, 41.2, 24.7, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BClO 2 [M+Na]: 329.1450, found: 329.1453. [α] 20 D = -8.1 (c S11
= 0.87, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 24.3 min and t R2 : 26.6 min). (S)-2-(2-(3-bromophenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3na) A colorless oil (39.2 mg, 56% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.38 (br, 1H), 7.31 7.29 (m, 1H), 7.15 7.14 (m, 2H), 5.72 5.62 (m, 1H), 5.00 4.95 (m, 2H), 2.97 2.89 (m, 1H), 2.39 2.32 (m, 2H), 1.27 (dd, J = 15.6, 6.5 Hz, 1H), 1.14 (s, 6H), 1.13 (s, 6H), 1.11 (dd, J = 15.5, 9.3 Hz, 1H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 149.3, 136.6, 130.8, 129.7, 129.0, 126.0, 122.2, 116.5, 83.1, 43.3, 41.2, 24.7, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 24 BBrO 2 [M+Na]: 373.0945, found: 373.0948. [α] 20 D = -6.3 (c = 0.83, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 95/5, flow rate 0.5 ml/min, detection 220 nm, t R1 : 19.5 min and t R2 : 21.0 min). (S)-2-(2-(3-methoxyphenyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3oa) A colorless oil (47.1 mg, 78% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.19 (t, J = 7.8 Hz, 1H), 6.84 6.70 (m, 3H), 5.76 5.65 (m, 1H), 5.02 4.93 (m, 2H), 3.81 (s, 3H), 2.98 2.90 (m, 1H), 2.43 2.30 (m, 2H), 1.27 (dd, J = 15.5, 7.1 Hz, 1H), 1.14 1.09 (m, 13H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 159.4, 148.6, 137.1, 129.0, 119.8, 116.0, 113.2, 111.2, 83.0, 55.1, 43.6, 41.4, 24.7, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 18 H 27 BO 3 [M+Na]: 325.1945, found: 325.1949. [α] 20 D = -6.4 (c = 0.74, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 22.2 min and t R2 : 24.2 min). tert-butyl S12
(S)-4-(1-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pent-4-en-2-yl)-1H-indole-1-carboxylate (3pa) A colorless oil (63.4 mg, 77% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 8.01 (d, J = 8.0 Hz, 1H), 7.59 (d, J = 3.7 Hz, 1H), 7.27 (d, J = 8.0 Hz, 1H), 7.13 (d, J = 7.4 Hz, 1H), 6.76 (d, J = 3.7 Hz, 1H), 5.75 5.64 (m, 1H), 5.01 4.90 (m, 2H), 3.45 3.37 (m, 1H), 2.56 2.41 (m, 2H), 1.69 (s, 9H), 1.39 (dd, J = 15.4, 7.1 Hz, 1H), 1.31 (dd, J = 15.4, 8.8 Hz, 1H), 1.09 (s, 6H), 1.05 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 149.9, 139.4, 137.1, 135.1, 129.5, 124.9, 124.3, 120.1, 116.0, 112.7, 106.2, 83.4, 83.0, 43.1, 37.9, 28.2, 24.6 ppm. HRMS (m/z, ESI): Calcd. for C 24 H 34 BNO 4 [M+Na]: 434.2473, found: 434.2463. [α] 20 D = -10.0 (c = 0.32, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 14.2 min and t R2 : 18.2 min). (S)-4,4,5,5-tetramethyl-2-(2-(naphthalen-2-yl)pent-4-en-1-yl)-1,3,2-dioxaborolane (3qa) A colorless oil (52.2 mg, 81% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.82 7.78 (m, 3H), 7.67 (s, 1H), 7.48 7.40 (m, 3H), 5.78 5.68 (m, 1H), 5.03 4.93 (m, 2H), 3.20 3.13 (m, 1H), 2.55 2.42 (m, 2H), 1.39 (dd, J = 15.4, 6.5 Hz, 1H), 1.28 (dd, J = 15.4, 10.5 Hz, 1H), 1.10 (s, 6H), 1.09 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 144.3, 137.1, 133.5, 132.2, 127.7, 127.6, 127.6, 126.2, 125.7, 125.0, 116.2, 83.0, 43.5, 41.5, 24.7, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 21 H 27 BO 2 [M+Na]: 345.1996, found: 345.1990. [α] 20 D = -26.9 (c = 0.98, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 97% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 254 nm, t R1 : 12.3 min and t R2 : 14.1 min). 2-((1R,2S,4S)-3-cinnamylbicyclo[2.2.1]hept-5-en-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3ra) S13
A white solid (47.7 mg, 71% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.40 (d, J = 7.5 Hz, 2H), 7.33 (t, J = 7.4 Hz, 2H), 7.22 (t, J = 7.3 Hz, 1H), 6.44 (d, J = 15.9 Hz, 1H), 6.34 6.26 (m, 1H), 6.16 (dd, J = 5.6, 2.8 Hz, 1H), 6.08 (dd, J = 5.2, 3.0 Hz, 1H), 2.86 (brs, 1H), 2.74 2.68 (m, 2H), 2.18 2.10 (m, 1H), 1.75 1.69 (m, 1H), 1.65 (d, J = 8.0 Hz, 1H), 1.30 1.28 (m, 13H), 1.02 (dd, J = 9.4, 1.4 Hz, 1H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 137.9, 137.9, 135.8, 131.0, 130.4, 128.5, 126.8, 126.0, 83.0, 45.5, 44.4, 44.4, 41.7, 37.9, 25.0, 25.0 ppm. HRMS (m/z, ESI): Calcd. for C 22 H 29 BO 2 [M+Na]: 359.2153, found: 359.2150. [α] 20 D = -15.2 (c = 1.04, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 67% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 220 nm, t R1 : 13.7 min and t R2 : 15.3 min). (S,E)-4,4,5,5-tetramethyl-2-(5-phenyl-2-(o-tolyl)pent-4-en-1-yl)-1,3,2-dioxaborolane (3bb) A colorless oil (58.6 mg, 81% yield from l-2b; 59.4 mg, 82% yield from b-2b) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.31 7.26 (m, 5H), 7.22 7.17 (m, 2H), 7.13 7.06 (m, 2H), 6.39 (d, J = 15.8 Hz, 1H), 6.17 6.10 (m, 1H), 3.37 3.30 (m, 1H), 2.55 2.43 (m, 2H), 2.40 (s, 3H), 1.34 (dd, J = 15.4, 6.3 Hz, 1H), 1.24 (dd, J = 15.3, 9.8 Hz, 1H), 1.07 (s, 6H), 1.03 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 144.9, 137.8, 135.6, 131.3, 129.9, 129.2, 128.4, 126.8, 126.0, 126.0, 126.0, 125.6, 82.9, 42.7, 36.4, 24.6, 24.5, 19.9 ppm. HRMS (m/z, ESI): Calcd. for C 24 H 31 BO 2 [M+Na]: 385.2309, found: 385.2314. [α] 20 D = +16.9 (c = 1.66, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 95% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 254 nm, t R1 : 25.5 min and t R2 : 40.4 min). (S,E)-4,4,5,5-tetramethyl-2-(2-(o-tolyl)hex-4-en-1-yl)-1,3,2-dioxaborolane (3bc) S14
A colorless oil (45.6 mg, 76% yield from l-2c; 51.6 mg, 86% yield from b-2c) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.22 7.03 (m, 4H), 5.45 5.31 (m, 2H), 3.23 3.15 (m, 1H), 2.37 (s, 3H), 2.31 2.16 (m, 2H), 1.63 (d, J = 5.8 Hz, 3H), 1.28 (dd, J = 15.4, 6.4 Hz, 1H), 1.15 (dd, J = 15.2, 9.8 Hz, 1H), 1.07 (s, 6H), 1.04 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.3, 135.6, 129.8, 129.6, 126.4, 126.0, 125.9, 125.3, 82.8, 42.3, 36.3, 24.6, 24.6, 19.9, 17.9 ppm. HRMS (m/z, ESI): Calcd. for C 19 H 29 BO 2 [M+Na]: 323.2153, found: 323.2156. [α] 20 D = +6.6 (c = 0.61, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 97% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 9.2 min and t R2 : 10.9 min). (S,E)-4,4,5,5-tetramethyl-2-(2-(o-tolyl)oct-4-en-1-yl)-1,3,2-dioxaborolane (3bd) A colorless oil (33.4 mg, 51% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.22 7.02 (m, 4H), 5.41 5.27 (m, 2H), 3.24 3.16 (m, 1H), 2.37 (s, 3H), 2.30 2.20 (m, 2H), 1.94 (dt, J = 7.0, 6.8 Hz, 2H), 1.35 1.28 (m, 2H), 1.28 (dd, J = 15.3, 6.2 Hz, 1H), 1.16 (dd, J = 15.3, 10.0 Hz, 1H), 1.06 (s, 6H), 1.04 (s, 6H), 0.85 (t, J = 7.3 Hz, 3H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.2, 135.6, 132.0, 129.8, 128.5, 126.0, 125.9, 125.3, 82.8, 42.4, 36.3, 34.7, 24.6, 24.5, 22.7, 19.9, 13.6 ppm. HRMS (m/z, ESI): Calcd. for C 21 H 33 BO 2 [M+Na]: 351.2466, found: 351.2470. [α] 20 D = +3.7 (c = 0.43, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 93% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 18.5 min and t R2 : 20.7 min). (S,E)-2-(5-cyclohexyl-2-(o-tolyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3be) S15
A colorless oil (27.2 mg, 37% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.21 7.02 (m, 4H), 5.34 5.21 (m, 2H), 3.22 3.15 (m, 1H), 2.36 (s, 3H), 2.28 2.18 (m, 2H), 1.88 1.82 (m, 1H), 1.70 1.60 (m, 4H), 1.28 0.97 (m, 20H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.2, 138.2, 135.7, 129.7, 126.1, 125.8, 125.6, 125.3, 82.8, 42.5, 40.7, 36.4, 33.1, 33.1, 26.2, 26.1, 24.6, 24.5, 19.9 ppm. HRMS (m/z, ESI): Calcd. for C 24 H 37 BO 2 [M+Na]: 391.2779, found: 391.2786. [α] 20 D = +8.3 (c = 0.63, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 91% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 98/2, flow rate 0.5 ml/min, detection 220 nm, t R1 : 23.5 min and t R2 : 25.8 min). (S,E)-4,4,5,5-tetramethyl-2-(2-(o-tolyl)hepta-4,6-dien-1-yl)-1,3,2-dioxaborolane (3bf) A colorless oil (31.2 mg, 50% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.23 7.04 (m, 4H), 6.31 6.22 (m, 1H), 6.07 (dd, J = 15.1, 10.6 Hz, 1H), 5.65 5.57 (m, 1H), 5.10 (d, J = 16.7 Hz, 1H), 4.97 (d, J = 10.1 Hz, 1H), 3.29 3.21 (m, 1H), 2.43 2.29 (m, 5H), 1.28 (dd, J = 15.2, 6.2 Hz, 1H), 1.18 (dd, J = 15.3, 9.6 Hz, 1H), 1.07 (s, 6H), 1.04 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 144.9, 137.3, 135.6, 133.5, 132.4, 129.9, 126.0, 125.9, 125.5, 114.9, 82.9, 42.2, 36.2, 24.6, 24.5, 19.8 ppm. HRMS (m/z, ESI): Calcd. for C 20 H 29 BO 2 [M+Na]: 335.2153, found: 335.2156. [α] 20 D = +15.6 (c = 0.48, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 199/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 44.3 min and t R2 : 52.0 min). 2-((S,E)-5-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)-2-(o-tolyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3, 2-dioxaborolane (3bg) S16
A colorless oil (30.9 mg, 40% yield) was isolated by column chromatography (30:1 to 10:1 petroleum ether/ethyl acetate). δ 7.20 7.03 (m, 4H), 5.73 5.65 (m, 1H), 5.46 (dd, J = 15.3, 7.7 Hz, 1H), 4.45 (dt, J = 7.6, 6.4 Hz, 1H), 4.05 (dd, J = 8.0, 6.1 Hz, 1H), 3.51 (t, J = 8.0 Hz, 1H), 3.26 3.19 (m, 1H), 2.40 2.24 (m, 5H), 1.42 (s, 3H), 1.38 (s, 3H), 1.25 (dd, J = 15.3, 6.2 Hz, 1H), 1.16 (dd, J = 15.3, 9.9 Hz, 1H), 1.06 (s, 6H), 1.03 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 144.6, 135.5, 133.8, 129.9, 128.9, 126.0, 125.9, 125.6, 109.0, 82.9, 69.5, 41.7, 35.9, 26.7, 25.9, 24.6, 24.5, 19.8 ppm. HRMS (m/z, ESI): Calcd. for C 23 H 35 BO 4 [M+Na]: 409.2521, found: 409.2525. [α] 20 D = +28.1 (c = 0.72, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 220 nm, t R1 : 12.5 min and t R2 : 14.5 min). 2-((R,E)-5-((S)-2,2-dimethyl-1,3-dioxolan-4-yl)-2-(o-tolyl)pent-4-en-1-yl)-4,4,5,5-tetramethyl-1,3, 2-dioxaborolane (3bg ) A colorless oil (29.3 mg, 38% yield) was isolated by column chromatography (30:1 to 10:1 petroleum ether/ethyl acetate). δ 7.19 7.02 (m, 4H), 5.69 5.61 (m, 1H), 5.38 (dd, J = 15.3, 7.8 Hz, 1H), 4.41 (dt, J = 7.6, 6.4 Hz, 1H), 3.97 (dd, J = 8.0, 6.2 Hz, 1H), 3.41 (t, J = 8.0 Hz, 1H), 3.26 3.18 (m, 1H), 2.35 2.30 (m, 5H), 1.39 (s, 3H), 1.36 (s, 3H), 1.26 (dd, J = 15.3, 6.4 Hz, 1H), 1.17 (dd, J = 15.4, 9.8 Hz, 1H), 1.06 (s, 6H), 1.03 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 144.6, 135.6, 133.5, 129.8, 129.1, 126.0, 125.9, 125.5, 109.0, 82.9, 69.4, 41.9, 35.8, 26.7, 25.9, 24.5, 24.5, 19.9 ppm. [α] 20 D = +44.6 (c = 0.67, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 220 nm, t R1 : 12.1 min and t R2 : 13.7 min). 2-((2S)-2-(cyclohex-2-en-1-yl)-2-(o-tolyl)ethyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3bh) S17
A colorless oil (30.6 mg, 47% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.22 (d, J = 7.6 Hz, 1H), 7.15 (t, J = 7.0 Hz, 1H), 7.10 7.02 (m, 2H), 5.92 (d, J = 9.6 Hz, 1H), 5.78 5.75 (m, 1H), 3.07 3.00 (m, 1H), 2.39 (s, 3H), 2.23 (br, 1H), 1.97 (br, 2H), 1.69 1.66 (m, 1H), 1.46 1.38 (m, 3H), 1.17 1.13 (m, 2H), 0.98 (s, 12H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 144.8, 136.3, 129.8, 129.7, 128.0, 126.4, 125.9, 125.3, 82.8, 42.7, 40.3, 27.3, 25.5, 24.5, 24.5, 21.6, 20.3 ppm. HRMS (m/z, ESI): Calcd. for C 21 H 31 BO 2 [M+Na]: 349.2309, found: 349.2313. [α] 20 D = -36.0 (c = 0.95, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 96% ee (DAICEL CHIRALCEL AS, eluent, hexane/2-propanol = 98/2, flow rate 0.5 ml/min, detection 220 nm, t R1 : 18.9 min and t R2 : 21.2 min). 2-((2S)-2-(cyclopent-2-en-1-yl)-2-(o-tolyl)ethyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3bi) A colorless oil (43.7 mg, 70% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.24 (d, J = 7.6 Hz, 1H), 7.16 (t, J = 7.0 Hz, 1H), 7.10 7.02 (m, 2H), 5.91 5.89 (m, 1H), 5.83 5.81 (m, 1H), 3.05 2.99 (m, 1H), 2.90 2.89 (m, 1H), 2.39 2.30 (m, 4H), 2.24 2.19 (m, 1H), 1.78 1.69 (m, 1H), 1.42 1.27 (m, 2H), 1.21 (dd, J = 14.8, 11.2 Hz, 1H), 0.99 (s, 6H), 0.98 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 145.0, 136.0, 133.5, 131.6, 129.8, 126.6, 125.9, 125.3, 82.8, 53.7, 40.7, 32.0, 28.5, 24.5, 24.5, 20.2 ppm. HRMS (m/z, ESI): Calcd. for C 20 H 29 BO 2 [M+Na]: 335.2153, found: 335.2156. [α] 20 D = +47.4 (c = 0.61, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL OD, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 12.9 min and t R2 : 14.3 min). (S)-4,4,5,5-tetramethyl-2-(2-phenyl-2-(o-tolyl)ethyl)-1,3,2-dioxaborolane (3bj) 7 S18
A colorless oil (34.8 mg, 54% yield) was isolated by column chromatography (98:2 petroleum ether/ethyl acetate). 1 H NMR (400 MHz, CDCl 3 ) δ 7.41 (d, J = 7.6 Hz, 1H), 7.26 7.20 (m, 5H), 7.17 7.11 (m, 3H), 4.51 (t, J = 8.4 Hz, 1H), 2.33 (s, 3H), 1.62 (d, J = 8.1 Hz, 2H), 1.11 (s, 6H), 1.06 (s, 6H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 146.5, 144.1, 136.2, 130.2, 128.2, 127.8, 126.8, 125.9, 125.7, 83.1, 42.3, 24.6, 24.6, 20.0 ppm. [α] 20 D = +28.0 (c = 1.61, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 90% ee (DAICEL CHIRALCEL AS, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 15.7 min and t R2 : 17.2 min). Derivatization of enantioenriched -allylboronic esters (3S,3aR,7S,7aS)-7-iodo-3-(o-tolyl)octahydrobenzofuran (6) 8 A solution of 3bh (97.8 mg, 0.3 mmol) in THF (2 ml) and H 2 O (2 ml) was added NaBO 3 4H 2 O (277.2 mg, 1.8 mmol) at room temperature. The reaction mixture was stirred for 12h and quenched by saturated aq. Na 2 S 2 O 3 (2 ml). The mixture was extracted with ethyl acetate (3 X 10 ml). The combined organic layer was washed with water and brine, dried by anhydrous NaSO 4 and concentrated in vacuo to give a crude product. Purification by flash column chromatography (silica gel, eluting with 30:1 to 10:1 petroleum ether/ethyl acetate) afforded (S)-2-((S)-cyclohex-2-en-1-yl)-2-(o-tolyl)ethan-1-ol (52.5 mg, 81% yield). To a mixture of (S)-2-((S)-cyclohex-2-en-1-yl)-2-(o-tolyl)ethan-1-ol (43 mg, 0.2 mmol, 96% ee) and NaHCO 3 (50.4 mg, 0.6 mmol) in dry CH 3 CN (4 ml), was added I 2 (152.4 mg, 0.6 mmol) at -30 o C. The reaction was stirred for 2 hours and aqueous saturated aq. Na 2 S 2 O 3 was added to the mixture until the system became clear. The mixture was extracted with ethyl acetate (3 X 10 ml). The combined organic layer was washed with water and brine, dried by anhydrous NaSO 4. The solvent S19
was removed in vacuum and the residue was purified by column chromatography (30:1 petroleum ether/ethyl acetate) to afford compound 6 as a colorless oil (60.2 mg, 88% yield, 96% ee). The stereochemistry of 6 was assigned through 1 H NMR (NOE). 1 H NMR (400 MHz, CDCl 3 ) δ 7.26 7.13 (m, 4H), 4.45 4.32 (m, 3H), 3.91 (dd, J = 8.6, 7.4 Hz, 1H), 3.55 (q, J = 8.0 Hz, 1H), 2.57 2.51 (m, 1H), 2.33 (s, 3H), 2.25 2.21 (m, 1H), 2.00 1.90 (m, 1H), 1.79 1.71 (m, 1H), 1.65 1.49 (m, 3H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 138.9, 136.5, 130.5, 126.6, 126.5, 125.6, 84.4, 73.4, 45.3, 42.8, 35.1, 33.3, 25.0, 23.0, 20.0 ppm. HRMS (m/z, ESI): Calcd. for C 15 H 19 IO [M+Na]: 365.0373, found: 365.0360. [α] 20 D = +77.3 (c = 0.67, CHCl 3 ). HPLC analysis: 96% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 0.5 ml/min, detection 254 nm, t R1 : 12.7 min and t R2 : 20.1 min). (S)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-(o-tolyl)butanal (7) 9 O O B O O 3, DCM, -78 C O B O 3ba 7 A solution of 3ba (57.2 mg, 0.2 mmol) in dichloromethane (20mL) was treated with ozone at 78 C and s rred un l comple on (TLC control). The reaction mixture was flushed with air and argon and triphenylphopshine (104.8 mg, 0.4 mmol) was added. The resulting solution was allowed to warm slowly to room temperature and stirred for 2 hours before being dried (anhydrous NaSO 4 ), filtered and concentrated in vacuo to give a crude product. Purification by flash column chromatography (silica gel, eluting with 10:1 to 2:1 petroleum ether/ethyl acetate) afforded the aldehyde 7 (47.2 mg, 82% yield, 97% ee). 1 H NMR (400 MHz, CDCl 3 ) δ 9.67 (t, J = 2.2 Hz, 1H), 7.23-7.06 (m, 4H), 3.79 3.71 (m, 1H), 2.75 (dd, J = 7.4, 1.5 Hz, 2H), 2.43 (s, 3H), 1.25 (d, J = 7.9 Hz, 2H), 1.09 (s, 6H), 1.07 (s, 6H) ppm. 13 C NMR(100 MHz, CDCl 3 ) δ 202.3, 143.7, 135.4, 130.3, 126.3, 126.1, 125.8, 83.2, 52.3, 30.7, 29.7, 24.6, 19.8 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 25 BO 3 [M+Na]: 311.1789, found: 311.1792. [α] 20 D = +12.8 (c = 0.60, CHCl 3 ). HPLC analysis directly (no oxidization): 97% ee (DAICEL CHIRALCEL AS, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 6.9 min and t R2 :7.7 min). (S)-2-(o-tolyl)pent-4-en-1-ol (8) 10 S20
A solution of 3ba (52 mg, 0.18 mmol) in THF (2 ml) and H 2 O (2 ml) was added NaBO 3 4H 2 O (166.0 mg, 1.1 mmol) at room temperature. The reaction mixture was stirred for 12h and quenched by saturated aq. Na 2 S 2 O 3 (2 ml). The mixture was extracted with ethyl acetate (3 X 10 ml). The combined organic layer was washed with water and brine, dried by anhydrous NaSO 4 and concentrated in vacuo to give a crude product. Purification by flash column chromatography (silica gel, eluting with 30:1 to 10:1 petroleum ether/ethyl acetate) afforded (S)-2-(o-tolyl)pent-4-en-1-ol (8) (30.1 mg, 95% yield, 97% ee). 1 H NMR (400 MHz, CDCl 3 ) δ 7.23 7.14 (m, 4H), 5.79 5.70 (m, 1H), 5.09 4.98 (m, 2H), 3.83 3.77 (m, 2H), 3.31 3.24 (m, 1H), 2.55 2.33 (m, 5H), 1.37 (brs, 1H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 140.0, 136.9, 136.4, 130.6, 126.4, 126.3, 125.9, 116.4, 66.5, 42.7, 36.7, 19.9 ppm. HRMS (m/z, ESI): Calcd. for C 12 H 16 O [M+Na]: 199.1093, found: 199.1091. [α] 20 D = +36.9 (c = 0.49, CHCl 3 ). HPLC analysis: 97% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 98/2, flow rate 1.0 ml/min, detection 220 nm, t R1 : 13.8 min and t R2 : 18.4 min). (S)-4,4,5,5-tetramethyl-2-((3-methylene-2,3-dihydro-1H-inden-1-yl)methyl)-1,3,2-dioxaborolane (9) 11 To a mixture of 3da (70 mg, 0.2 mmol), PdCl 2 (PPh 3 ) 2 (7.0 mg, 0.01mmol), K 2 CO 3 (55.2 mg, 0.4 mmol) and DMF (1 ml) were added under a argon atmosphere followed by one drop of hydrazine monohydrate by syringe. The mixture was heated at 100 o C for 24 h. The resulting mixture was cooled to room temperature and it was extracted with ether (3 X 10 ml). The combined organic layer was washed with water and brine, dried by anhydrous NaSO 4. The solvent was removed in vacuum and the residue was purified by column chromatography (50:1 to 30:1 petroleum S21
ether/ethyl acetate) to afford compound 9 as a colorless oil (33.5 mg, 62% yield, 94% ee). 1 H NMR (400 MHz, CDCl 3 ) δ 7.49 (d, J = 6.9 Hz, 1H), 7.32 (d, J = 7.4 Hz, 1H), 7.27-7.19 (m, 2H), 5.44 (t, J = 2.4 Hz, 1H), 5.03 (t, J = 1.9 Hz, 1H), 3.45 3.39 (m, 1H), 3.12 3.05 (m, 1H), 2.46 2.39 (m, 1H), 1.40 (dd, J = 15.0, 5.0 Hz, 1H), 1.29 (s, 6H), 1.27 (s, 6H) 1.08 (dd, J = 15.5, 9.8 Hz, 1H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 151.8, 149.5, 140.4, 128.3, 126.5, 124.3, 120.4, 102.3, 83.2, 40.9, 38.2, 24.9, 24.7 ppm. HRMS (m/z, ESI): Calcd. for C 17 H 23 BO 2 [M+Na]: 293.1683, found: 293.1679. [α] 20 D = -1.3 (c = 0.77, CHCl 3 ). HPLC analysis after oxidized by NaBO 3 4H 2 O: 94% ee (DAICEL CHIRALCEL AS, eluent, hexane/2-propanol = 99/1, flow rate 1.0 ml/min, detection 220 nm, t R1 : 24.3 min and t R2 : 26.9 min). (E)-(5-(4-methoxyphenyl)pent-1-ene-1,4-diyl)dibenzene (10) 12 To the flame-dried tube was added Pd(OAc) 2 (4.6 mg, 0.02 mmol), (+/-)-BINAP (12.4 mg, 0.02 mmol) and dried THF (0.5 ml). The solution was stirred at glove box for 30min, followed by addition of 3bb (72.4 mg, 0.2 mmol), NaOH (120 mg, 3.0 mmol) and THF (1.5 ml). After taken out of glove box, to the tube was added 1-bromo-4-methoxybenzene (55.8 mg, 0.3 mmol) and degassed H 2 O (0.1 ml). The mixture was stirred at 70 o C for 48h and then diluted by DCM (10 ml). After filtered through celite, the filtrate was evacuated under rotary evaporation. The residue was purified by fast column chromatography with petroleum ether/ethyl acetate (50/1) as the eluent to get colorless oil, (E)-(5-(4-methoxyphenyl)pent-1-ene-1,4-diyl)dibenzene 10 (58.1 mg, 85% yield, 94% ee). 1 H NMR (400 MHz, CDCl 3 ) δ 7.33 7.19 (m, 7H), 7.14 7.10 (m, 2H), 7.00 (d, J = 8.5 Hz, 2H), 6.80 (d, J = 8.5 Hz, 2H), 6.39 (d, J = 15.8 Hz, 1H), 6.11 6.04 (m, 1H), 3.80 (s, 3H), 3.35 3.27 (m, 1H), 2.98 2.85 (m, 2H), 2.63 2.54 (m, 2H), 2.17 (s, 3H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 157.8, 142.8, 137.8, 136.1, 132.6, 131.4, 130.2, 130.1, 128.8, 128.4, 126.9, 126.2, 126.1, 126.0, 125.8, 113.5, 55.2, 42.8, 41.6, 38.8, 19.8 ppm. HRMS (m/z, ESI): Calcd. for C 25 H 26 O [M+Na]: 365.1876, found: 365.1876. [α] 20 D = -10.2 (c = 0.55, CHCl 3 ). HPLC analysis: 94% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 254 nm, t R1 : 13.4 min and t R2 :16.7 min). S22
Synthesis of (-)-Preclamol 13 9-Borabicyclo[3.3.1]nonane (9-BBN) (0.5 M) in hexanes (1.8 ml) was added dropwise to 3oa (181.2 mg, 0.6 mmol) under argon. The mixture was stirred at room temperature until all starting material was consumed (18 h), as indicated by TLC. Following addition of 3 M NaOH (1.0 ml) and 30% H 2 O 2 (0.9 ml), the mixture was heated at 50 0 C for 1.5 h. After cooling to room temperature, the reaction was quenched by saturated aq. Na 2 S 2 O 3 (2 ml). The mixture was extracted with ethyl acetate (3 X 15 ml). The combined organic layer was washed with water and brine, dried by anhydrous NaSO 4. The solvent was removed in vacuum and the residue was purified by column chromatography (20:1 DCM/MeOH) to afford compound (s)-11 as a colorless oil (90.0 mg, 71% yield, 95% ee). 1 H NMR (400 MHz, CDCl 3 ) δ 7.25 (t, J = 7.7 Hz, 1H), 6.81 6.76 (m, 3H), 3.80 (s, 3H), 3.72 (d, J = 6.7 Hz, 2H), 3.58 (dt, J = 6.3, 1.7 Hz, 2H), 2.79 2.72 (m, 1H), 2.31 (brs, 2H), 1.89 1.80 (m, 1H), 1.64 1.55 (m, 1H), 1.50 1.43 (m, 2H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 159.8, 144.0, 129.6, 120.4, 114.1, 111.7, 67.3, 62.5, 55.2, 48.3, 30.3, 28.1 ppm. HRMS (m/z, ESI): Calcd. for C 12 H 18 O 3 [M+Na]: 233.1148, found: 233.1146. [α] 20 D = +8.2 (c = 0.47, CHCl 3 ). HPLC analysis: 95% ee (DAICEL CHIRALCEL OJ, eluent, hexane/2-propanol = 95/5, flow rate 1.0 ml/min, detection 220 nm, t R1 : 46.9 min and t R2 : 54.9 min). The obtained (s)-11 was unambiguously assigned as S-configuration by comparison of its optical rotation with the literature reported 13b ([α] 22 D = +10.7 (c = 1.0, CHCl 3 ). A solution of (S)-11 (90 mg, 0.43 mmol) in dry dichloromethane (4 ml) was cooled to 0 0 C, Et 3 N (217 mg, 2.15 mmol) was added, followed by distilled MsCl (122 mg, 1.1 mmol) dropwise over 1 min. The reaction mixture was stirred for 12 h at room temperature. Then, it was quenched with saturated aq. NaHCO 3 (5 ml). The aqueous layer was extracted with DCM (3 x 10 ml). The combined organic layers were dried over anhydrous Na 2 SO 4, filtered and concentrated on a rotary evaporator to afford the crude dimesylate. Dimesylate was directly mixed with n-prnh 2 (1 ml, 12.5 mmol) and stirred at room temperature for 24 h. The resulting mixture was diluted with S23
DCM (10 ml) and washed with saturated Na 2 CO 3 solution. Purification by flash chromatography (silica gel, 20:1 DCM/MeOH) afforded O-methylpreclamol as white waxy solid (65.5 mg, 66% yield). O-Methylpreclamol (64 mg, 0.26 mmol) was mixed with 48% HBr (1mL) under argon in a 25-mL tube. The mixture was stirred at 120 0 C for 2 h. The resulting mixture was cooled to 0 0 C and basified by dropwise addition of saturated aq. Na 2 CO 3. Then, the mixture was extracted with DCM (4 x 10 ml). The combined organic layers were dried over anhydrous Na 2 SO 4, filtered and concentrated on a rotary evaporator. The residue was purified by flash chromatography (1:1 hexane/acetone) to give pure (-)-Preclamol as a yellow oil (49 mg, 86% yield, 97% ee). 1 H NMR (400 MHz, CDCl 3 ) δ 7.19 (t, J = 7.8 Hz, 1H), 6.81 6.73 (m, 3H), 3.28 (d, J = 11.3 Hz, 1H), 3.15 (d, J = 11.2 Hz, 1H), 3.02 2.96 (m, 1H), 2.51 2.37 (m, 2H), 2.12 1.98 (m, 3H), 1.87 1.82 (m, 2H), 1.67 1.47 (m, 3H), 0.90 (t, J = 7.3 Hz, 3H) ppm. 13 C NMR (100 MHz, CDCl 3 ) δ 156.8, 145.2, 129.8, 117.6, 114.7, 114.2, 61.1, 61.0, 53.9, 41.7, 30.0, 25.0, 19.1, 12.0 ppm. HRMS (m/z, ESI): Calcd. for C 14 H 21 NO [M+H]: 220.1696, found: 220.1696. [α] 20 D = -16.7 (c = 0.33, CHCl 3 ). HPLC analysis: 97% ee (DAICEL CHIRALCEL AD, eluent, hexane/2-propanol = 95/5, flow rate 0.8 ml/min, detection 220 nm, t R1 : 17.8 min and t R2 : 21.4 min). References: 1. D. J. M. Snelders, G. Koten, R. J. M. K. Gebbink, J. Am. Chem. Soc. 2009, 131, 11407 2. S. Hattori, H. Imaseki, J. Am. Chem. Soc. 1959, 81, 4424 3. M. J. Bosiak, M. Rakowiecki, K. J. Oriowska, D. Kedziera, J. Adams, Dyes and Pigments 2013, 99, 803 4. A. R. Brown, G. A. Molander, J. Org. Chem. 2006, 71, 9681 5. P. Zhang, L. A. Brozek, J. P. Morken, J. Am. Chem. Soc. 2010, 132, 10686 6. a) J. Chen, D. Li, H. Ma, L. Cun, J. Zhu, J. Deng, J. Liao, Tetrahedron Lett. 2008, 6921; b) D. Wang, P. Cao, B. Wang, T. Jia, Y. Lou, M. Wang, J. Liao, Org. Lett. 2015, 17, 2420 7. Smith, K. B.; Logan, K. M.; You, W.; Brown, M. K. Chem. - Eur. J. 2014, 20, 12032. 8. Z. W. Jiao, S. Y. Zhang, C. He, Y. Q. Tu, S. H. Wang, F. M. Zhang, Y. Q. Zhang, H. Li, Angew. Chem. Int. Ed. 2012, 51, 8811 S24
9. Turnbull, B. W. H.; Evans, P. A. J. Am. Chem. Soc. 2015, 137, 6156 10. Matsuda, N.; Hirano, K.; Satoh, T.; Miura, M. J. Am. Chem. Soc. 2013, 135, 4934. 11. R. Mirabdolbaghi, T. Dudding, Tetrahedron 2012, 68, 1988 12. T. Jia, P. Cao, D. Wang, Y. Lou, J. Liao, Chem.- Eur. J. 2015, 21, 4918 13. a) J. Hu, Y. Lu, Y. Li, J. Zhou, Chem. Commun. 2013, 49, 9425; b) J. Y. Hamilton, D. Sarlah, E. M. Carreira, Angew. Chem. Int. Ed. 2015, 54, 7644. S25
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