Supporting Information

Supporting Information Straightforward xanthate-mediated synthesis of functional γ-thiolactones and their application to polymer synthesis and modification Marvin Langlais, Ihor Kulai, Olivier Coutelier* and Mathias Destarac* Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France *coutelier@chimie.ups-tlse.fr *destarac@chimie.ups-tlse.fr Materials... 2 General techniques... 2 Synthesis of diethyl allyphosphonate... 4 Synthesis of xanthate salt XA0... 4 Synthesis of xanthates XA1 and XA2... 5 Synthesis of monoadducts M1-9... 6 Synthesis of thiolactones TL1-9... 15 NMR Spectra... 23 General procedures of polymer end-functionalizations... 52 Step-growth polymerization... 61 S1

Materials The following chemicals were used as received; DL-3-methyl-2-butanol (Acros Organics, 98%), carbon disulfide (CS 2, Sigma-Aldrich, > 99%), methyl bromoacetate (Sigma-Aldrich, 98%), methyl 2-bromopropionate (Alfa Aesar, 97%), lauroyl peroxide (LPO, Fluka, > 95%), 1-heptene (Alfa Aesar, 98+%), dimethyl vinylphosphonate (DMVP, Sigma-Aldrich, > 95%), 1H, 1H, 2H-perfluoro-1-hexene (Alfa Aesar, 97%), 1H, 1H, 2H-perfluoro-1-decene (Alfa Aesar, 99%), N-phenylmaleimide (Alfa Aesar, 98+%), diethyl phosphate (Sigma-Aldrich, 98%), allyl bromide (Acros Organics, 99%), tetrabutylammonium bromide (TBAB, Acros Organics, 99+%), silica gel 60 (SiO 2, Sigma-Aldrich, 40-63µm), potassium hydroxide (KOH, VWR, 86,8%) potassium carbonate (K 2 CO 3, Sigma-Aldrich, anhydrous, 99%), sodium sulfate (Na 2 SO 4, anhydrous, Prolabo, 99%), benzyl acrylate (BzA, Alfa Aesar, 97%, stabilized with ca 150 ppm 4-methoxyphenol), methyl acrylate (MA, Sigma-Aldrich, 99%, contains < 100 ppm monomethyl ether hydroquinone as inhibitor), 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate (TFOA, Sigma-Aldrich, 97%, contains inhibitor), methoxypoly(ethylene glycol) amine (MPEG-NH 2, Sigma-Aldrich, M n ~ 2000 g.mol -1 ), poly(ethylene glycol) bis(3- aminopropyl) terminated (PEG-diNH 2, Sigma-Aldrich, M n ~ 1500 g.mol -1 ), poly(dimethylsiloxane) bis(3-aminopropyl) terminated (PDMS-diNH 2, Sigma-Aldrich, M n ~ 2500 g.mol -1 ), poly(ethylene glycol) diacrylate (PEG-diacrylate, Sigma-Aldrich, M n ~ 575 g.mol -1 ). The following solvents were used as received; tetrahydrofuran (THF, Sigma-Aldrich, HPLC grade), acetone (Sigma-Aldrich, HPLC grade), dichloromethane (DCM, Sigma-Aldrich, HPLC grade), petroleum ether (Sigma-Aldrich, HPLC grade), ethyl acetate (EtOAc, Sigma- Aldrich, HPLC grade), hexane (Sigma-Aldrich, HPLC grade), toluene (Sigma-Aldrich, HPLC grade). General techniques Nuclear magnetic resonance spectra ( 1 H, 13 C, 31 P and 19 F NMR) were recorded at 298 K on a Bruker Avance 300 MHz instrument. 1 H NMR spectra were recorded at 300.13 MHz and coupling constants (J) are reported to ± 0.5 Hz. The resonance multiplicities are described as s (singlet), d (doublet), t (triplet), q (quartet) or m (multiplet). 13 C NMR spectra were recorded at 75.47 MHz, 31 P NMR spectra were recorded at 121.49 MHz and 19 F NMR spectra were recorded at 282.38 MHz. Chemical shifts δ are reported in parts per million (ppm) and are S2

referenced to the residual solvent peak (CDCl 3 : H = 7.26 ppm and C = 77.16 ppm; D 2 O: H = 4.79 ppm). IR spectroscopy analyses were carried out using a Thermo Nicolet Nexus spectrometer with Diamond ATR. 16 scans from 600 to 4000 cm -1 were taken and absorptions were reported in wavenumbers (cm -1 ). Size-exclusion chromatography (SEC) analyses were performed on a system composed of an Agilent technologies guard column (PLGel20 µm, 50 7.5 mm) and a set of three Waters columns (1 Styragel HR 3, 7.8 300 mm and 2 Styragel HR 4, 7.8 300 mm). Detection was conducted using a Wyatt Optilab rex refractive index detector. Analyses were performed in THF at 308 K at a flow rate of 1.0 ml/min. Polystyrene (PS) standards (580-7.5 10 6 g.mol -1 ) were used for calibration. High-resolution mass spectroscopy analyses (EI and CI-CH 4 ) were performed using a GCT 1er Waters apparatus. Matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) analyses were performed on Waters MALDI-TOF Micro MX equipped with a nitrogen laser emitting at λ = 357 nm. All analyses were carried out with 1,8-dihydroxy-9(10H)-anthracenone (Ditrhanol) as matrix and NaI salt as cationic agent. S3

Synthesis of diethyl allyphosphonate Diethyl allylphosphonate DEAP C 7 H 15 O 3 P M = 178.08 g.mol -1 Diethylphosphite (13.81 g, 0.1 mol), allyl bromide (15 g, 0.12 mol), K 2 CO 3 (21 g, 0.15 mol) and TBAB (1.61 g, 5 mmol) were refluxed in THF (200 ml) during 24 h. Then the reaction mixture was concentred under reduced pressure, solubilised in deionized water (400 ml) and extracted with DCM (3 100 ml). The organic phase was dried over anhydrous Na 2 SO 4 and concentrated under reduced pressure. The oil was distillated under vacuum to yielded DEAP as a colorless liquid (16.1 g, 90%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.82-5.70 (m, 1H, CH 2 =CHCH 2 P), 5.22-5.13 (m, 2H, CH 2 =CHCH 2 P), 4.12-4.02 (m, 4H, O=P(CH 2 CH 3 ) 2 ), 2.62-2.52 (m, 2H, CH 2 =CHCH 2 P), 1.30-1.25 (t, J = 7.1 Hz, 6H, O=P(CH 2 CH 3 ) 2 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 127.62 (CH 2 =CHCH 2 P), 120.05 (CH 2 =CHCH 2 P), 62.02 (O=P(OCH 2 CH 3 ) 2 ), 32.74-30.89 (CH 2 =CHCH 2 P), 16.50 (O=P(OCH 2 CH 3 ) 2 ). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 27.18. Synthesis of xanthate salt XA0 Potassium O-(3-methylbutan-2-yl) carbonodithioate XA0 C 6 H 11 KOS 2 M = 201.99 g.mol -1 3-methylbutan-2-ol (101 g, 1.13 mol), KOH (63.65 g, 1.13 mol) and CS 2 (90.7 g, 1.19 mol) were stirred in THF (500 ml) at room temperature until total dissolution of KOH. Then, the solution was concentrated under reduced pressure, triturated with pentane and filtered on Büchner. The compound XA0 was obtained as a yellow solid (185 g, 80%). S4

1 H NMR (300.13 MHz, D 2 O, 298K) δ = 5.31 (p, J = 6.4 Hz, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 2.07-1.84 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.27 (d, J = 6.4 Hz, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.96 (d, J= 6.9 Hz, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, D 2 O, 298K) δ = 232.60 (C=S), 86.33 ((CH 3 ) 2 CHCH(O)CH 3 ), 32.76 ((CH 3 ) 2 CHCH(O)CH 3 ), 17.72 ((CH 3 ) 2 CHCH(O)CH 3 ), 17.58 ((CH 3 ) 2 CHCH(O)CH 3 ), 15.81 ((CH 3 ) 2 CHCH(O)CH 3 ). IR = 2968, 1456, 1379, 1067, 1027 cm -1 Synthesis of xanthates XA1 and XA2 Methyl 2-((((3-methylbutan-2-yl)oxy)carbonothioyl)thio)propanoate XA1 C 10 H 18 O 3 S 2 M = 250.07 g.mol -1 Methyl 2-bromopropionate (35.05 g, 0.21 mol) was added dropwise to a stirred solution of XA0 (40.5 g, 0.2 mol) in acetone (200 ml) at 0 C. After stirring for 3 h, the mixture was filtered off to remove the formed KBr. The solvent was concentrated under reduced pressure to yield a yellow oil (43.1 g, 86%). XA1 was used without additional purification. 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.56-5.48 (p, J = 6.3 Hz, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.41-4.30 (m, 1H, CH(CH 3 )CO 2 CH 3 ), 3.74 (s, 3H, CO 2 CH 3 ), 2.02-1.93 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.56-1.52 (dd, J = 7.4, 2.7 Hz, 3H, CH(CH 3 )CO 2 CH 3 ), 1.29-1.27 (dd, J= 6.4, 4.9 Hz, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.96-0.93 (dd, J= 6.9, 1.8 Hz, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 211.53-211.47 (C=S), 172.05 (CO 2 CH 3 ), 86.25-86.13 ((CH 3 ) 2 CHCH(O)CH 3 ), 52.84-52.81 (CO 2 CH 3 ), 46.57 (CH(CH 3 )CO 2 CH 3 ), 32.72 ((CH 3 ) 2 CHCH(O)CH 3 ), 18.27-17.90 ((CH 3 ) 2 CHCH(O)CH 3 ), 17.11-16.94 (CH(CH 3 )CO 2 CH 3 ), 15.84-15.74 ((CH 3 ) 2 CHCH(O)CH 3 ). IR = 2966, 1741, 1241, 1161, 1046, 1024 cm -1 S5

Methyl 2-((((3-methylbutan-2-yl)oxy)carbonothioyl)thio)acetate XA2 C 9 H 16 O 3 S 2 M = 236.05 g.mol -1 Methyl bromoacetate (35.1 g, 0.21 mol) was added dropwise to a stirred solution of XA0 (40.5 g, 0.2 mol) in acetone (200 ml) at 0 C. After stirring for 3 h, the mixture was filtered off to remove the formed KBr. The solvent was concentrated under reduced pressure to yield a yellow oil (42.2 g, 89%). XA2 was used without additional purification. 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.53-5.45 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 3.87 (s, 2H, CH 2 CO 2 CH 3 ), 3.73 (s, 3H, CO 2 CH 3 ), 2.03-1.92 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.28-1.25 (d, J = 6.4 Hz, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.94-0.92 (d, J = 6.8 Hz, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 211.83 (C=S), 168.50 (CO 2 CH 3 ), 86.49 ((CH 3 ) 2 CHCH(O)CH 3 ), 52.81 (CO 2 CH 3 ), 37.38 (CH 2 CO 2 CH 3 ), 32.69 ((CH 3 ) 2 CHCH(O)CH 3 ), 18.14-17.87 ((CH 3 ) 2 CHCH(O)CH 3 ), 15.74 ((CH 3 ) 2 CHCH(O)CH 3 ). IR = 2964, 1743, 1242, 1157, 1048, 1024 cm -1 Synthesis of monoadducts M1-9 Methyl 2-methyl 4-((((3-methylbutan-2-yl)oxy) carbonothioyl)thio)nonanoate M1 O S S O O C 17 H 32 O 3 S 2 M = 348.18 g.mol -1 XA1 (9.1 g, 36 mmol), 1-heptene (3.14 g, 32 mmol) and LPO (1.91 g, 4.8 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freezepump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; petroleum ether/ethyl acetate 95:5). M1 was obtained as a yellow oil (10.3 g, 92%). S6

1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.51-5.46 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 3.69-3.60 (m, 1H, SCHCH 2 CH(CH 3 )CO 2 CH 3 ), 3.60-3.58 (m, 3H, CO 2 CH 3 ), 2.62-2.58 (m, 1H, SCHCH 2 CH(CH 3 )CO 2 CH 3 ), 2.03-1.88 (m, 2H, SCHCH 2 CH(CH 3 )CO 2 CH 3 ), 1.65-1.33 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3, CH 2 (CH 2 ) 3 CH 3 ), 1.25-1.20 (m, 2H, CH 2 CH 2 (CH 2 ) 2 CH 3 ), 1.20-1.18 (m, 7H, CH(CH 3 )CO 2 CH 3, (CH 2 ) 2 (CH 2 ) 2 CH 3 ), 1.12-1.10 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.90-0.87 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.87-0.79 (m, 3H, (CH 2 ) 4 CH 3 ); 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 213.80-213.70 (C=S), 176.38-176.35 (CO 2 CH 3 ), 85.18-85.02 ((CH 3 ) 2 CHCH(O)CH 3 ), 51.58 (CO 2 CH 3 ), 49.14-48.59 (SCHCH 2 CH(CH 3 )CO 2 CH 3 ), 38.16-37.54 (SCHCH 2 CH(CH 3 )CO 2 CH 3 ), 37.31-37.16 (SCHCH 2 CH(CH 3 )CO 2 CH 3 ), 35.25-34.75 (CH 2 (CH 2 ) 3 CH 3 ), 32.67 ((CH 3 ) 2 CHCH(O)CH 3 ), 31.60 ((CH 2 ) 2 CH 2 CH 2 CH 3 ), 26.32-26.20 (CH 2 CH 2 (CH 2 ) 2 CH 3 ), 22.46 ((CH 2 ) 3 CH 2 CH 3 ), 18.17 18.08 ((CH 3 ) 2 CHCH(O)CH 3 ), 17.07 16.99 (CH(CH 3 )CO 2 CH 3 ), 15.71-15.69 ((CH 3 ) 2 CHCH(O)CH 3 ), 13.96 (SCH(CH 2 ) 4 CH 3 ). IR = 2960, 2931, 2873, 1738, 1228, 1047, 1024 cm -1 HRMS (CI-CH4) calc. for [C 17 H 32 O 3 S 2 + H] + : 349.1871 Found 349.1861 Methyl 4-((((3-methylbutan-2-yl)oxy)carbonothioyl)thio)nonanoate M2 C 16 H 30 O 3 S 2 M = 334.16 g.mol -1 XA2 (8.3 g, 37 mmol), 1-heptene (3.24 g, 33 mmol) and LPO (1.97 g, 4.95 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freezepump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; petroleum ether/ethyl acetate 95:5). M2 was obtained as a yellow oil (10.1 g, 90%). S7

1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.57 5.49 (p, J = 6.3 Hz, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 3.74-3.64 (m, 1H, SCHCH 2 CH 2 CO 2 CH 3 ), 3.63 (s, 3H, CO 2 CH 3 ), 2.47-2.40 (m, 2H, SCHCH 2 CH 2 CO 2 CH 3 ), 2.07-1.94 (m, 2H, CH 2 (CH 2 ) 3 CH 3 ), 1.94-1.60 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.64-1.58 (m, 2H, SCHCH 2 CH 2 CO 2 CH 3 ), 1.44-1.27 (m, 2H, CH 2 CH 2 (CH 2 ) 2 CH 3 ), 1.27-1.23 (m, 7H, (CH 2 ) 2 (CH 2 ) 2 CH 3, (CH 3 ) 2 CHCH(O)CH 3 ), 0.94-0.92 (d, J = 6.8 Hz, 6H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.87-0.82 (m, 3H, (CH 2 ) 4 CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 214.00 213.93 (C=S), 173.51 173.49 (CO 2 CH 3 ), 85.40-85.37 ((CH 3 ) 2 CHCH(O)CH 3 ), 51.68 (CO 2 CH 3 ), 50.26-50.18 (SCHCH 2 CH 2 CO 2 CH 3 ), 34.59-34.29 (CH 2 (CH 2 ) 3 CH 3 ), 32.76 ((CH 3 ) 2 CHCH(O)CH 3 ), 31.66 ((CH 2 ) 2 CH 2 CH 2 CH 3 ), 31.45-31.40 (SCHCH 2 CH 2 CO 2 CH 3 ), 29.66-29.31 (SCHCH 2 CH 2 CO 2 CH 3 ), 26.57-26.50 (CH 2 CH 2 (CH 2 ) 2 CH 3 ), 22.55 ((CH 2 ) 3 CH 2 CH 3 ), 18.25-17.95 ((CH 3 ) 2 CHCH(O)CH 3 ), 15.79 ((CH 3 ) 2 CHCH(O)CH 3 ), 14.06 ((CH 2 ) 4 CH 3 ). IR = 2959, 2929, 2857, 1741, 1228, 1049, 1024 cm -1 HRMS (CI-CH4) calc. for [C 16 H 30 O 3 S 2 + H] + : 335.1715 Found 335.1701 Methyl 5-(diethoxyphosphoryl)-2-methyl-4-((((3-methylbutan-2-yl) oxy)carbonothioyl)pentanoate M3 O S S P O O O O O C 17 H 33 O 6 PS 2 M = 428.15 g.mol -1 XA1 (8.75 g, 35 mmol), DEAP (5.52 g, 31 mmol) and LPO (1.89 g, 4.7 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freezepump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). M3 was obtained as a yellow oil (11.9 g, 90%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.54-5.46 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4,15 4.02 (m, 4H, O=P(OCH 2 CH 3 ) 2 ), 4.02-3.89 (m, 1H, CHS), 3.62 (s, 3H, CO 2 CH 3 ), 2.75-1.63 (m, 6H, CH 2 P, (CH 3 ) 2 CHCH(O)CH 3, CH 2 CHCO 2 CH 3 ), 1.32-1.23 (m, 9H, O=P(OCH 2 CH 3 ) 2, S8

CH 3 CHCO 2 CH 3 ), 1.17-1.14 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.92-0.90 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 212.69-215.66 (C=S), 176.25-176.07 (CO 2 CH 3 ), 85.86-85.72 ((CH 3 ) 2 CHCH(O)CH 3 ), 62.01-61.87 (O=P(OCH 2 CH 3 ) 2 ), 51.84-51.80(CO 2 CH 3 ), 43.73-43.58 (CHS), 37.79 37.32 (CH 2 P), 37.21-37.16 ((CH 3 ) 2 CHCH(O)CH 3 ), 33.42 32.72 (CH 2 CH 2 CO 2 CH 3 ), 31.62 31.10 (CHCO 2 CH 3 ), 18.29-18.24 ((CH 3 ) 2 CHCH(O)CH 3 ), 17.93-17.82 (CH 3 CHCO 2 CH 3 ), 16.64-16.54 (O=P(OCH 2 CH 3 ) 2 ), 15.87-15.82 ((CH 3 ) 2 CHCH(O)CH 3 ). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.77, 26.75. IR = 2975, 1735, 1238, 1042, 1026, 965, 842 cm -1 HRMS (CI-CH4) calc. for [C 17 H 33 O 6 PS 2 + H] + : 429.1534 Found 429.1533 Methyl 5-(diethoxyphosphoryl)-4-((((3-methylbutan-2-yl) oxy)carbonothioyl)pentanoate M4 C 16 H 31 O 6 PS 2 M = 414.13 g.mol -1 XA2 (8.7 g, 37 mmol), DEAP (5.8 g, 33 mmol) and LPO (1.9 g, 4.95 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freeze-pump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). M4 was obtained as a yellow oil (12.1 g, 89%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.46-5.42 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.06 4.00 (m, 4H, O=P(OCH 2 CH 3 ) 2 ), 4.00-3.98 (m, 1H, CHS), 3.55 (s, 3H, CO 2 CH 3 ), 2.39-1.89 (m, 7H, CH 2 P, (CH 3 ) 2 CHCH(O)CH 3, CH 2 CH 2 CO 2 CH 3 ), 1.25-1.22 (m, 6H, O=P(OCH 2 CH 3 ) 2 ), 1.22-1.17 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.86-0.83 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). S9

13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 212.17 (C=S), 172.80 172.77 (CO 2 CH 3 ), 85.62 ((CH 3 ) 2 CHCH(O)CH 3 ), 61.86-61.66 (O=P(OCH 2 CH 3 ) 2 ), 51.53 (CO 2 CH 3 ), 44.52 44.46 (CHS), 32.53 ((CH 3 ) 2 CHCH(O)CH 3 ), 32.47 32.26 (CH 2 P), 31.17-31.14 (CH 2 CH 2 CO 2 CH 3 ), 29.09-28.74 (CH 2 CH 2 CO 2 CH 3 ), 18.07-17.76 ((CH 3 ) 2 CHCH(O)CH 3 ), 16.37-16.29 (O=P(OCH 2 CH 3 ) 2 ), 15.64 ((CH 3 ) 2 CHCH(O)CH 3 ). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.53, 26.51. IR = 2977, 1738, 1238, 1045, 1025, 963, 842 cm -1 HRMS (CI-CH4) calc. for [C 16 H 31 O 6 PS 2 + H] + : 415.1378 Found 415.1390 Methyl 4-(dimethoxyphosphoryl)-2-methyl-4-((((3-methylbutan-2-yl) oxy)carbonothioyl)butanoate M5 C 14 H 27 O 6 PS 2 M = 386.10 g.mol -1 XA1 (9.0 g, 36 mmol), DMVP (4.49 g, 33 mmol) and LPO (1.9 g, 4.95 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freeze-pump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was stopped and purified with flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). M5 was obtained as a yellow oil (10.1 g, 79%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.46-5.39 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.27-4.16 (m, 1H, CHP), 3.73-3.66 (m, 6H, O=P(OCH 3 ) 2 ), 3.57-3.56 (m, 3H, CO 2 CH 3 ), 2.78-1.98 (m, 2H, CH 2 CH(CH 3 )CO 2 CH 3 ), 2.44-1.51 (m, 1H, CH 2 CH(CH 3 )CO 2 CH 3 ), 1.97-1.82 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.23-1.17 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.15-1.08 (m, 1H, CH 2 CH(CH 3 )CO 2 CH 3 ), 0.88-0.83 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 211.65-211.35 (C=S), 175.85 (CO 2 CH 3 ), 87.01 ((CH 3 ) 2 CHCH(O)CH 3 ), 53.92-53.40 (O=P(OCH 3 ) 2 ), 51.77 (CO 2 CH 3 ), 43.75-41.23 (CHP), 36.82-36.21 (CH 2 CH(CH 3 )CO 2 CH 3 ), 32.86-32.68 (CH 2 CH(CH 3 )CO 2 CH 3 ), 32.53 S10

((CH 3 ) 2 CHCH(O)CH 3 ), 18.06-17.77 ((CH 3 ) 2 CHCH(O)CH 3 ), 16.79-16.71 (CH 2 CH(CH 3 )CO 2 CH 3 ), 15.60 ((CH 3 ) 2 CHCH(O)CH 3 ). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.7, 26.6, 26.5, 26.4. IR = 2955, 1736, 1243, 1035, 823 cm -1 HRMS (CI-CH4) calc. for [C 14 H 27 O 6 PS 2 + H] + : 387.1065 Found 387.1059 Methyl 4-(dimethoxyphosphoryl)-4-((((3-methylbutan-2-yl) oxy)carbonothioyl)butanoate M6 C 13 H 25 O 6 PS 2 M = 372.08 g.mol -1 XA2 (14.2 g, 60 mmol), DMVP (2.72 g, 20 mmol) and LPO (1.2 g, 3 mmol) were introduced in a Schlenk tube. The solution was degassed with three freeze-pump-thaw cycles and sealed under vacuum. After heating and stirring during 5 h at 90 C, reaction mixture was stopped and purified with flash chromatography (SiO 2 ; ethyl acetate/petroleum ether 8:2) was used to recover the unreacted XA2 and (SiO 2 ; dichloromethane/ethyl acetate 8:2). M6 was obtained as a yellow oil (3.13 g, 42%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.47-5.42 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.31 4.19 (m, 1H, CHP), 3.75-3.70 (m, 6H, O=P(OCH 3 ) 2 ), 3.59 (s, 3H, CO 2 CH 3 ), 2.51-2.45 (m, 2H, CH 2 CH 2 CO 2 CH 3 ), 2.43-1.87 (m, 2H, CH 2 CH 2 CO 2 CH 3 ), 2.02-1.87 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.25-1.21 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.89-0.86 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 211.80-211.52 (C=S), 175.73 (CO 2 CH 3 ), 87.23-87.21 ((CH 3 ) 2 CHCH(O)CH 3 ), 53.74-53.43 (O=P(OCH 3 ) 2 ), 51.64 (CO 2 CH 3 ), 44.60-42.64 (CHP), 32.65 ((CH 3 ) 2 CHCH(O)CH 3 ), 30.95 29.21 (CH 2 CH 2 CO 2 CH 3 ), 25.10-24.87 (CH 2 CH 2 CO 2 CH 3 ), 17.99-17.77 ((CH 3 ) 2 CHCH(O)CH 3 ), 15.63 ((CH 3 ) 2 CHCH(O)CH 3 ). S11

31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.3, 26.2. IR = 2957, 1738, 1245, 1037, 830 cm -1 HRMS (CI-CH4) calc. for [C 13 H 25 O 6 PS 2 + H] + : 373.0908 Found 373.0916 Methyl 5,5,6,6,7,7,8,8,8-nonafluoro-2-methyl-4-((((3-methylbutan-2-yl) oxy)carbonothioyl)octanoate M7 C 16 H 21 F 9 O 3 S 2 M = 496.08 g.mol -1 XA1 (4.47 g, 18 mmol), 1H, 1H, 2H-perfluoro-1-hexene (4.01 g, 16 mmol) and LPO (0.99 g, 2.5 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freeze-pump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; hexane/ethyl acetate 95:5). M7 was obtained as a yellow oil (3.55 g, 45%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.59-5.48 (s, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.91-4.67 (m, 1H, SCHCH 2 CH(CH 3 )), 3.66 (s, 3H, CO 2 CH 3 ), 2.93-2.65 (m,1h, SCHCH 2 CH(CH 3 )), 2.49-1.49 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ); SCHCH 2 CH(CH 3 )), 1.31-1.21 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ; SCHCH 2 CH(CH 3 )), 0.96-0.92 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 209.43 (C=S), 175.47 (CO 2 CH 3 ), 11987-108.40 (CH(CF 2 ) 3 CF 3 ), 87.46-87.05 ((CH 3 ) 2 CHCH(O)CH 3 ), 51.93 (CO 2 CH 3 ), 50.15-49.30CH(CF 2 ) 3 CF 3 ), 36.45 (SCHCH 2 CH(CH 3 )), 32.63 ((CH 3 ) 2 CHCH(O)CH 3 ), 30.96-30.57 (SCHCH 2 CH(CH 3 )), 18.24-15.38 ((CH 3 ) 2 CHCH(O)CH 3; (SCHCH 2 CH(CH 3 )). 19 F{ 1 H} NMR (282.38 MHz, CDCl 3, 298K) δ = -80.80 (CH(CF 2 ) 3 CF 3 )), -106.13 - -116.56 (CH(CF 2 CF 2 CF 2 CF 3 )), -119.98 - -120.52 (CH(CF 2 CF 2 CF 2 CF 3 )), -124.74 - -127.44 (CH(CF 2 CF 2 CF 2 CF 3 )). S12

IR = 2974, 1740, 1238, 1215, 1135, 1043, 1023, 736 cm -1 HRMS (CI-CH4) calc. for [C 16 H 21 F 9 O 3 S 2 + H] + : 497.0867 Found 497.0858 Methyl 5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heptadecafluoro-2-methyl -4-((((3-methylbutan-2-yl)oxy)carbonothioyl)dodecanoate M8 C 20 H 21 F 17 O 3 S 2 M = 696.07 g.mol -1 XA1 (3.83 g, 16 mmol), 1H, 1H, 2H-perfluoro-1-decene (6.20 g, 14 mmol) and LPO (0.83 g, 2.1 mmol) were dissolved in toluene (5 ml) in a Schlenk tube. The solution was degassed with three freeze-pump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; hexane/ethyl acetate 9:1). M8 was obtained as a yellow oil (5.52 g, 56%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 5.58-5.47 (s, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.87-4.67 (m, 1H, SCHCH 2 CH(CH 3 )), 3.70-3.68 (m, 3H, CO 2 CH 3 ), 2.92-2.68 (m,1h, SCHCH 2 CH(CH 3 )), 2.14-1.92 (m, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.58-1.53 (m, 2H, SCHCH 2 CH(CH 3 )), 1.32-1.20 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ; SCHCH 2 CH(CH 3 )), 0.97-0.93 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 209.33 (C=S), 175.54 (CO 2 CH 3 ), 129.01-115.52 (CH(CF 2 ) 7 CF 3 ), 87.48 ((CH 3 ) 2 CHCH(O)CH 3 ), 52.71-51.79 (CO 2 CH 3 ), 46.50 (CH(CF 2 ) 3 CF 3 ), 36.48 (SCHCH 2 CH(CH 3 )), 32.71 ((CH 3 ) 2 CHCH(O)CH 3 ), 18.30-15.44 ((CH 3 ) 2 CHCH(O)CH 3; (SCHCH 2 CH(CH 3 )). 19 F{ 1 H} NMR (282.38 MHz, CDCl 3, 298K) δ = -80.74 (CH(CF 2 ) 7 CF 3 )), -105.86 - -116.28 (CH(CF 2 (CF 2 ) 6 CF 3 )), -118.96 - -119.33 (CH(CF 2 CF 2 (CF 2 )CF 3 )), -121.67 - -121.88 (CH(CF 2 CF 2 (CF 2 ) 3 CF 2 CF 2 CF 3 )), -122.70 (CH(CF 2 ) 5 CF 2 CF 2 CF 3 )), -126.04 (CH(CF 2 ) 6 CF 2 CF 3 )). S13

IR = 2975, 1739, 1243, 1208, 1152, 1043, 1024, 910, 735 cm -1 HRMS (CI-CH4) calc. for [C 20 H 21 F 17 O 3 S 2 + H] + : 697.0739 Found 697.0743 Methyl 2-(4-((((3-methylbutan-2-yl)oxy)carbonothioyl)thio) -2,5-dioxo-1-phenylpyrrolidin-3-yl)propanoate M9 C 20 H 25 NO 5 S 2 M = 423.17 g.mol -1 XA1 (9.43 g, 38 mmol), N-phenylmaleimide (6.07 g, 35 mmol) and LPO (2.00 g, 5 mmol) were dissolved in toluene (7 ml) in a Schlenk tube. The solution was degassed with three freeze-pump-thaw cycles and sealed under vacuum. After heating and stirring during 16 h at 90 C, reaction mixture was purified with flash chromatography (SiO 2 ; hexane/ethyl acetate 7:3). M9 was obtained as a yellow viscous oil (11.5 g, 78%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 7.51-7.34 (m, 5H, N-C 6 H 5 ), 5.62-5.45 (s, 1H, (CH 3 ) 2 CHCH(O)CH 3 ), 4.65-4.41 (m, 1H, SCH(CO)CH), 3.74-3.70 (m, 3H, CO 2 CH 3 ), 3.58-3.20 (m, 2H, SCH(CO)CH(CO)CH(CH 3 )), 2.07-1.93 (1H, (CH 3 ) 2 CHCH(O)CH 3 ), 1.54-1.44 (m, 3H, CH(CO)CH(CH 3 )), 1.35 1.29 (m, 3H, (CH 3 ) 2 CHCH(O)CH 3 ), 0.99-0.93 (m, 6H, (CH 3 ) 2 CHCH(O)CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 210.19-209.83 (C=S), 175.27-171.68 (C(O)NC(O) et CO 2 CH 3 ), 132.17 ((CO) 2 N-C), 129.13-126.40 ((CO) 2 N-C-C 5 H 5 ), 87.42 ((CH 3 ) 2 CHCH(O)CH 3 ), 52.38 (CO 2 CH 3 ), 49.54-47.93 (SCH(CO)CH(CO)CH(CH 3 )), 39.68-38.97 (SCH(CO)CH(CO)CH(CH 3 )), 32.71 ((CH 3 ) 2 CHCH(O)CH 3 ), 18.35-17.85 ((CH 3 ) 2 CHCH(O)CH 3 ), 15.89-14.78 ((CH 3 ) 2 CHCH(O)CH 3 ; SCH(CO)CH(CO)CH(CH 3 )). IR = 2964, 1784, 1718, 1597, 1382, 1245, 1192, 1045, 751 cm -1 HRMS (CI-CH4) calc. for [C 20 H 25 NO 5 S 2 + H] + : 424.1252 Found 424.1272 S14

Synthesis of thiolactones TL1-9 3-methyl-5-pentyldihydrothiophen-2(3H)-one TL1 C 10 H 18 OS M = 186.11 g.mol -1 M1 (3.48 g, 10 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into dry bath maintained at 190 C. After heating during 15 min, it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 48 h with periodical cooling down and evacuated to remove formed methanol. Finally, crude reaction was purified by flash chromatography (SiO 2 ; ethyl acetate/petroleum ether 9:1). TL1 was obtained as a colorless liquid (1.73 g, 93%). 1 H NMR (300 MHz, CDCl 3, 298K) δ = 3.74-3.69 (m, 1H, SCHCH 2 CH), 2.71-2.47 (m, 2H, SCHCH 2 CH), 2.18-2.03 (m, 1H, SCHCH 2 CH), 1.91-1.68 (m, 2H, CH 2 CH 2 (CH 2 ) 2 CH 3 ), 1.54-1.32 (m, 2H, CH 2 (CH 2 ) 3 CH 3 ), 1.32-1.21 (m, 4H, (CH 2 ) 2 (CH 2 ) 2 CH 3 ), 1.20-1.13 (m, 3H, CHCH 3 ), 0.92-0.84 (m, 3H, (CH 2 ) 4 CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 211.06 209.92 (C=O), 48.91-47.89 (SCHCH 2 CH), 47.54-45.59 (SCHCH 2 CH), 41.49-39.65 (SCHCH 2 CH), 36.83-36.47 (CH 2 (CH 2 ) 3 CH 3 ) 31.65-31.57 ((CH 2 ) 2 CH 2 CH 2 CH 3 ), 28.21-28.02 (CH 2 CH 2 (CH 2 ) 2 CH 3 ), 22.60-22.56 ((CH 2 ) 3 CH 2 CH 3 ), 15.50-14.54 (CHCH 3 ), 14.07 ((CH 2 ) 4 CH 3 ). IR = 2956, 2928, 2855, 1702, 1455, 954, 892 cm -1 HRMS (EI) calc. for [C 10 H 18 OS] +. : 186.1078 Found 186.1075 S15

5-pentyldihydrothiophen-2(3H)-one TL2 C 9 H 16 OS M = 172.09 g.mol -1 M2 (3.35 g, 10 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 48 h with periodical cooling down and evacuated to remove formed methanol. Finally, crude reaction was purified by flash chromatography (SiO 2 ; ethyl acetate/petroleum ether 9:1). TL2 was obtained as a colorless liquid (1.55 g, 90%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 3.85-3.78 (m, 1H, SCHCH 2 CH 2 ), 2.59-2.44 (m, 2H, SCHCH 2 CH 2 ), 2.43-1.79 (m, 2H, SCHCH 2 CH 2 ), 1.79-1.62 (m, 2H, CH 2 CH 2 (CH 2 ) 2 CH 3 ), 1.47-1.33 (m, 2H, CH 2 (CH 2 ) 3 CH 3 ), 1.32-1.19 (m, 4H, (CH 2 ) 2 (CH 2 ) 2 CH 3 ), 0.86 (t,j = 7.0 Hz, 3H, (CH 2 ) 4 CH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 208.60 (C=O), 51.41 (SCHCH 2 CH 2 ), 42.08 (SCHCH 2 CH 2 ), 36.47 (CH 2 (CH 2 ) 3 CH 3 ), 32.23 ((CH 2 ) 2 CH 2 CH 2 CH 3 ), 31.50 (SCHCH 2 CH 2 ), 27.97 (CH 2 CH 2 (CH 2 ) 2 CH 3 ), 22.46 ((CH 2 ) 3 CH 2 CH 3 ), 13.97 ((CH 2 ) 4 CH 3 ). IR = 2956, 2927, 2856, 1705, 1456, 1153, 1038 cm -1 HRMS (EI) calc. for [C 9 H 16 OS] +. : 172.0922 Found 172.0910 S16

Diethyl((4-methyl-5-oxotetrahydrotiophen-2-yl)methyl)phosphonate TL3 C 10 H 19 O 4 PS M = 266.07 g.mol -1 M3 (4.29 g, 10 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into a dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 1 h and finally cooled down and evacuated to remove formed methanol. Crude reaction was purified by flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). TL3 was obtained as a colorless oil (2.4 g, 90%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 4.18-4.05 (m, 4H, O=P(OCH 2 CH 3 ) 2 ), 4.05-3.90 (m, 1H, CHCH 2 P), 2.77-2.29 (m, 2H, CH 2 CH(CH 3 )), 2.28-2.07 (m, 2H, CHCH 2 P), 1.62-1.20 (m, 1H, CHCH 2 P), 1.35-1.29 (m, 6H, O=P(OCH 2 CH 3 ) 2 ), 1.19-1.14 (m, 3H, CH 2 CH(CH 3 )). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 209.89-208.93 (C=O), 62.19-62.0.2 (O=P(OCH 2 CH 3 ) 2 ), 48.70-45.36 (CHCH 2 P), 42.57 42.43 (CH 2 CH(CH 3 )),40.99-40.91 (CH 2 CH(CH 3 )), 34.15-31.73 (CHCH 2 P), 16.58-16.54 (O=P(OCH 2 CH 3 ) 2 ), 15.23-14.29 (CH 2 CH(CH 3 )). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.40, 26.36. IR = 2980, 2932, 2907, 2874, 1700, 1454, 1247, 1051, 1026, 964, 895 cm -1 HRMS (CI-CH4) calc. for [C 10 H 19 O 4 PS + H] + : 267.0820 Found 267.0826 S17

Diethyl((5-oxotetrahydrotiophen-2-yl)methyl)phosphonate TL4 C 9 H 17 O 4 PS M = 252.06 g.mol -1 M4 (4.15 g, 10 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into a dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 1 h and finally cooled down and evacuated to remove formed methanol. Crude reaction was purified by flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). TL4 was obtained as a colorless oil (2.3 g, 91%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 4.15-4.00 (m, 5H, CHCH 2 P, O=P(OCH 2 CH 3 ) 2 ), 2.63-2.45 (m, 3H, CH 2 CH 2 CO, CH 2 CH 2 CO), 2.29-2.08 (m, 2H, CHCH 2 P), 2.05-1.89 (m, 1H, CH 2 CH 2 CO), 1.32-1.25 (m, 6H, O=P(OCH 2 CH 3 ) 2 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 207.42 (C=O), 62.14-62.00 (O=P(OCH 2 CH 3 ) 2 ), 44.44-44.39 (CHCH 2 P), 41.83 (CH 2 CH 2 CO),33.70 33.39 (CHCH 2 P), 33.26 31.84 (CH 2 CH 2 CO), 16.51-16.43 (O=P(OCH 2 CH 3 ) 2 ). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.2. IR = 2982, 2907, 1704, 1251, 1051, 1026, 964, 807 cm -1 HRMS (CI-CH4) calc. for [C 9 H 17 O 4 PS + H] + : 253.0663 Found 253.0667 Dimethyl(4-methyl-5-oxotetrahydothiophen-2-yl)phosphonate TL5 C 7 H 13 O 4 PS M = 224.03 g.mol -1 S18

M5 (3.86 g, 10 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 1 h and finally cooled down and evacuated to remove formed methanol. Crude reaction was purified by flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). TL5 was obtained as a colorless oil (1.9 g, 85%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 3.98-3.73 (m, 1H, CHP), 3.72-3.64 (m, 6H, O=P(OCH 3 ) 2 ), 2.88-2.42 (m, 2H, CH 2 ), 2.09-1.69 (m, 1H, CHCH 3 ), 1.06-1.00 (m, 3H, CHCH 3 ). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 208.05-207.09 (C=O), 53.82-53.27 (O=P(OCH 3 ) 2 ), 47.30-44.42 (CHCH 3 ),40.05-37.20 (CHP), 34.11-33.66 (CH 2 ), 14.59-14.01 (CHCH 3 ). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 26.8, 24.7. IR = 2956, 1709, 1256, 1185, 1056, 1030, 956, 828 cm -1 HRMS (EI) calc. for [C 7 H 13 O 4 PS] +. : 224.0272 Found 224.0283 Dimethyl (5-oxotetrahydrothiophen-2-yl)phosphonate TL6 C 6 H 11 O 4 PS M = 210.01 g.mol -1 M6 (3.73 g, 10 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 1 h and finally cooled down and evacuated to remove formed methanol. Crude reaction was purified by flash chromatography (SiO 2 ; dichloromethane/ethyl acetate 8:2). TL6 was obtained as colorless oil (1.2 g, 57%). S19

1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 3.85-3.79 (m, 1H, CHP), 3.63-3.56 (m, 6H, O=P(OCH 3 ) 2 ), 2.60-2.33 (m, 2H, CH 2 CH 2 CHP), 2.32-2.17 (m, 2H, CH 2 CH 2 CHP). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 205.93-205.88 (C=O), 53.51-53.24 (O=P(OCH 3 ) 2 ), 42.58-40.52 (CHP), 39.84-39.77 (CH 2 CH 2 CHP), 25.58 (CH 2 CH 2 CHP). 31 P{ 1 H} NMR (121.49 MHz, CDCl 3, 298K) δ = 25.73. IR = 2956, 2853, 1714, 1257, 1052, 1031, 831 cm -1 HRMS (CI-CH4) calc. for [C 6 H 11 O 4 PS] +. : 211.0194 Found 211.0198 3-methyl-5-(perfluorobutyl)dihydrotiophen-2(3H)-one TL7 C 9 H 7 F 9 OS M = 334.01 g.mol -1 M7 (2.46 g, 5 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into a dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 72 h with periodical cooling down and evacuated to remove formed methanol. Finally, crude reaction was purified by flash chromatography (SiO 2 ; hexane/ethyl acetate 95:5). TL7 was obtained as a colorless liquid (1.1 g, 68%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 4.49-4.36 (m, 1H, CHCF 2 ), 2.73-2.61 (m, 2H, C(O)CH(CH 3 )CH 2 CH), 1.99 1.91 (dd, J = 12.1, 10.9 Hz 1H, C(O)CH(CH 3 )), 1.25-1.23 (d, J = 6.5 Hz, 3H, C(O)CH(CH 3 )). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 205.16 (C=O), 119.77-108.27 (CH(CF 2 ) 3 CF 3 ), 47.29 46.27 (CH(CF 2 ) 3 CF 3 ), 45.98-45.64 (C(O)CH(CH 3 )), 32.77 (C(O)CH(CH 3 )CH 2, 14.26 (C(O)CH(CH 3 )CH 2 ). S20

19 F{ 1 H} NMR (282.38 MHz, CDCl 3, 298K) δ = -81.10 (CH(CF 2 ) 3 CF 3 )), -112.07 - -117.68 (CH(CF 2 (CF 2 ) 2 CF 3 )), -121.25 (CH(CF 2 -CF 2 -CF 2 -CF 3 )), -126.05 (CH(CF 2 -CF 2 -CF 2 -CF 3 )). IR = 2979, 1720, 1534, 1222, 1235, 1172, 1135, 1140, 963, 906, 735 cm -1 HRMS (CI-CH4) calc. for [C 9 H 7 F 9 OS + H] + : 335.0152 Found 335.0164 3-methyl-5-(perfluorooctyl)dihydrotiophen-2(3H)-one TL8 C 13 H 7 F 17 OS M = 533.99 g.mol -1 M8 (5.49 g, 7.9 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 48 h with periodical cooling down and evacuated to remove formed methanol. Finally, crude reaction was purified by flash chromatography (SiO 2 ; hexane/ethyl acetate 95:5). TL8 was obtained as a white solid (2.58 g, 61%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 4.46-4.32 (m, 1H, CHCF 2 ), 2.86-2.61 (m, 2H, C(O)CH(CH 3 )CH 2 CH) ), 2.17-1.91 (m, 1H, C(O)CH(CH 3 )CH 2 CH), 1.26-1.21 (m, 3H, C(O)CH(CH 3 )). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 207.03 205.16 (C=O), 119.63-106.80 (CH(CF 2 ) 3 CF 3 ), 47.31 44.72 (CH(CF 2 ) 3 CF 3 ), 46.39-45.48 (C(O)CH(CH 3 )), 32.76-32.59 (C(O)CH(CH 3 )CH 2, 15.51-14.26 (C(O)CH(CH 3 )CH 2 ). S21

19 F{ 1 H} NMR (282.38 MHz, CDCl 3, 298K) δ = -81.01 - -81.08 (CH(CF 2 ) 7 CF 3 )), -111.91 - - 120.30 (CH(CF 2 (CF 2 ) 6 CF 3 )), -121.08 (CH(CF 2 CF 2 (CF2) 5 CF 3 )), -121.96 (CH(CF 2 CF 2 (CF 2 ) 3 CF 2 CF 2 CF 3 )), -122.86 (CH(CF 2 ) 5 CF 2 CF 2 CF 3 )), -126.39 (CH(CF 2 ) 6 CF 2 CF 3 )). IR = 2976, 1717, 1221, 2202, 1148, 1114, 971 cm -1 HRMS (CI-CH4) calc. for [C 13 H 7 F 17 OS + H] + : 535.0024 Found 535.0042 3-methyl-5-phenyldihydro-2H-thieno[2,3-c]pyrrole-2,4,6(3H,5H)-trione TL9 C 13 H 11 NO 3 S M = 261.05 g.mol -1 M9 (11.4 g, 27 mmol) was placed in a Schlenk tube, sealed under vacuum and immersed into dry bath maintained at 190 C. After heating during 15 min it was cooled down and evacuated under vacuum to remove formed COS, 2-methylbut-2-ene and methanol, this cycle was reproduced 3 times. Then the reaction was heated during 48 h with periodical cooling down and evacuated to remove formed methanol. Finally, crude reaction was purified by flash chromatography (SiO 2 ; hexane/ethyl acetate 6:4). TL9 was obtained as a brown pale solid (4.1 g, 59%). 1 H NMR (300.13 MHz, CDCl 3, 298K) δ = 7.52-7.25 (m, 5H, N-C 6 H 5 ) 4.79-4.77 (d,j = 8.3 Hz, 1H, SCH(CO)CH), 3.42-3.38 (m, 1H, CH(CH 3 )CHC(O)), 3.24-3.21 (m, 1H, C(O)CH(CH 3 )), 1.43-1.40 (d,j = 7.4 Hz, 3H, C(O)CH(CH 3 )). 13 C{ 1 H} NMR (75.47 MHz, CDCl 3, 298K) δ = 205.36 (SC=O), 174.51-173.44 (C(O)NC(O)), 131.10-126.22 (N-C 6 H 5 ), 49.42 (SCH(CO)), 48.95 (C(O)CH(CH 3 )), 46.73 (C(O)CH(CH 3 )CH(CO), 18.25 (C(O)CH(CH 3 )CH 2 ). IR = 2974, 1786, 1713, 1596, 1495, 1386, 1191 cm -1 HRMS (CI-CH4) calc. for [C 13 H 11 NO 3 S + H] + : 262.0538 Found 262.0544 S22

NMR Spectra: 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S1. 1 H NMR spectrum of DEAP. 13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S2. 13 C NMR spectrum of DEAP. S23

31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S3. 31 P NMR spectrum of DEAP. 1 H NMR (300.13 MHz, D2O, 298K) Figure S4. 1 H NMR spectrum of XA0. S24

13 C NMR (75.47 MHz, D2O, 298K) Figure S5. 13 C NMR spectrum of XA0. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S6. 1 H NMR spectrum of XA1. S25

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S7. 13 C NMR spectrum of XA1. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S8. 1 H NMR spectrum of XA2. S26

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S9. 13 C NMR spectrum of XA2. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S10. 1 H NMR spectrum of M1. S27

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S11. 13 C NMR spectrum of M1. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S12. 1 H NMR spectrum of M2. S28

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S13. 13 C NMR spectrum of M2. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S14. 1 H NMR spectrum of M3. S29

13 C NMR (75.47MHz, CDCl 3, 298K) Figure S15. 13 C NMR spectrum of M3. 31 P NMR (121.49MHz, CDCl 3, 298K) Figure S16. 31 P NMR spectrum of M3. S30

O S S P O O O O O 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S17. 1 H NMR spectrum of M4. 13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S18. 13 C NMR spectrum of M4. S31

O S S P O O O O O 31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S19. 31 P NMR spectrum of M4. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S20. 1 H NMR spectrum of M5. S32

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S21. 13 C NMR spectrum of M5. 31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S22. 31 P NMR spectrum of M5. S33

Figure S23. 31 P NMR spectrum of DMVP oligomers obtained after 16 h reaction time. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S24. 1 H NMR spectrum of M6. S34

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S25. 13 C NMR spectrum of M6. 31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S26. 31 P NMR spectrum of M6. S35

1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S27. 1 H NMR spectrum of M7. 13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S28. 13 C NMR spectrum of M7. S36

19 F NMR (282.38 MHz, CDCl 3, 298K) Figure S29. 19 F NMR spectrum of M7. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S30. 1 H NMR spectrum of M8. S37

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S31. 13 C NMR spectrum of M8. 19 F NMR (282.38 MHz, CDCl 3, 298K) Figure S32. 19 F NMR spectrum of M8. S38

1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S33. 1 H NMR spectrum of M9. 13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S34. 13 C NMR spectrum of M9. S39

1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S35. 1 H NMR spectrum of TL1. 13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S36. 13 C NMR spectrum of TL1. S40

31 P NMR (121.29 MHz, CDCl 3, 298K) Figure S41. 31 P NMR spectrum of TL3. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S42. 1 H NMR spectrum of TL4. S43

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S43. 13 C NMR spectrum of TL4. 31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S44. 31 P NMR spectrum of TL4. S44

31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S47. 31 P NMR spectrum of TL5. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S48. 1 H NMR spectrum of TL6. S46

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S49. 13 C NMR spectrum of TL6. 31 P NMR (121.49 MHz, CDCl 3, 298K) Figure S50. 31 P NMR spectrum of TL6. S47

1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S51. 1 H NMR spectrum of TL7. O S CF 2 F 2 C CF 2 F 3 C 13 C NMR (75.47 MHz, CDCl 3, 298K Figure S52. 13 C NMR spectrum of TL7. S48

19 F NMR (282.38 MHz, CDCl 3, 298K) Figure S53. 19 F NMR spectrum of TL7. 1 H NMR (300.13 MHz, CDCl 3, 298K) Figure S54. 1 H NMR spectrum of TL8. S49

13 C NMR (75.47 MHz, CDCl 3, 298K) Figure S55. 13 C NMR spectrum of TL8. 19F NMR (282.38 MHz, CDCl 3, 298K) Figure S56. 19 F NMR spectrum of TL8. S50

General procedures of polymer end-functionalizations Mono-functionalization: Typically, 200 mg (0.1 mmol) of MPEG-NH 2, thiolactone TL1 or TL5 (0.1 mmol) and 15 mg (0.1 mmol) of benzyl acrylate were placed in a Schlenk tube with a stir bar. The mixture was heated at 50 C under stirring with a dry bath during 6 h. The crude reaction mixture was analyzed by NMR, SEC and MALDI-TOF MS techniques. - 1 H and 31 P NMR analyses a b b CHCl 3 b b b b a Figure S59. 1 H NMR spectrum of the MPEG-NH 2 / TL5 / BzA crude product (300.13 MHz, CDCl 3 ). b) a) Figure S60. 31 P NMR spectra of a) thiolactone TL5 and b) MPEG-NH 2 / TL5 / BzA crude product (121.49 MHz, CDCl 3 ). S52

- SEC chromatograms a) MPEG-NH 2 MPEG-NH 2 / TL5 / BzA b) MPEG-NH 2 MPEG-NH 2 / TL1 / BzA M n = 3570 g.mol -1 M n = 2920 g.mol -1 M n = 3420 g.mol -1 M n = 2920 g.mol -1 19 21 23 25 27 29 Elution time (min) 19 21 23 25 27 29 Elution time (min) Figure S61. a) SEC analysis (RI traces) of MPEG-NH 2 and corresponding end-functionalized product with TL5 and BzA; b) SEC analysis (RI traces) of MPEG-NH 2 and corresponding end-functionalized product with TL1 and BzA. S53

- MALDI-TOF MS spectra a) n= 41 [M A +Na + ] n= 37 A B n= 47 0 n= 32 n= 53 b) [M A + Na + ] (n= 40) [M A + Na + ] (n= 41) m/z = 44 m/z = 44 [M B + Na + ] (n= 41) [M B + Na + ] (n= 42) [M A + K + ] (n= 40) [M A + K + ] (n= 41) Figure S62. a) MALDI-TOF MS spectrum of commercially available methoxypoly(ethylene glycol) amine (MPEG-NH 2 ); b) Zoom between 1850 and 1970 m/z of spectrum a). S54

a) n = 36 [M B + Na + ] A B n = 38 [M A + Na + ] b) [M B + Na + ] (n= 34) [M B + Na + ] (n= 35) [M B + Na + ] (n= 36) m/z = 44 m/z = 44 [M A + Na + ] (n= 34) [M B + K + ] (n= 34) [M A + Na + ] (n= 35) [M B + K + ] (n= 35) [M A + K + ] (n= 34) [M A + K + ] (n= 35) Figure S63. a) MALDI-TOF MS spectrum of MPEG-NH 2 end-functionalized with TL1 and BzA ; b) Zoom between 1930 and 2030 m/z of spectrum a). S55

Bi-functionalizations: Typically, MPEG-NH 2, PEG-diNH 2, or PDMS-diNH 2 (0.12 mmol), thiolactone (0.24 mmol) and acrylate compounds (0.24 mmol) were placed in a Schlenk tube with a stir bar. The mixture was stirred and heated at 50 C with a dry bath during 6 h. The crude reaction mixture was analyzed by NMR, SEC and MALDI-TOF MS techniques. - MALDI-TOF MS spectra A A n= 31 n= 32 B n= 30 A n= 31 n= 33 m/z= 44 m/z= 44 n= 36 B m/z= 44 n= 25 B n= 40 n= 19 Figure S64. MALDI-TOF MS spectrum of commercially available poly(ethylene glycol) PEG-diNH 2. S56

n= 28 n= 29 n= 30 n= 33 n= 29 n= 30 m/z = 44 n= 25 n= 9 n= 36 n= 6 n= 39 Figure S65. MALDI-TOF MS spectrum of PEG-diNH 2 end-functionalized with TL5 and BzA. 0 n= 12 n= 13 n= 14 n= 15 m/z= 74 m/z = 74 n= 7 [M+Na + ] n= 8 n= 9 m/z = 74 n= 10 n= 11 n= 12 n= 15 Figure S66. MALDI-TOF MS spectrum of commercially available PDMS-diNH 2. S57

n= 0 [M+Na + ] n= 1 n= 0 n= 1 m/z= 74 n= 2 n= 2 m/z= 74 n= 3 n= 4 n= 5 Figure S67. MALDI-TOF MS spectrum of PDMS end-functionalized with TL4 and BzA n= 0 [M+Na + ] n= 1 n= 2 n= 3 n= 2 m/z= 74 n= 4 m/z= 74 n= 3 n= 4 n= 5 Figure S68. MALDI-TOF MS spectrum of PDMS end-functionalized with TL5 and BzA. S58

n= 0 [M+Na + ] n= 1 n= 1 n= 2 m/z = 74 n= 2 n= 3 n= 3 m/z= 74 n= 4 n= 5 Figure S69. MALDI-TOF MS spectrum of PDMS end-functionalized with TL5 and MA. n= 0 [M+Na + ] n= 1 n= 1 n= 2 m/z= 74 n= 3 n= 2 m/z= 74 n= 3 n= 4 n= 5 Figure S70. MALDI-TOF MS spectrum of PDMS end-functionalized with TL5 and TFOA. S59

n= 0 [M+Na + ] n= 1 n= 1 n= 2 m/z= 74 n= 2 m/z= 74 n= 3 n= 4 n= 3 n= 4 n= 5 Figure S71. MALDI-TOF MS spectrum of PDMS end-functionalized with TL7 and BzA. n= 0 [M+Na + ] n= 1 n= 0 n= 1 n= 2 n= 2 n= 3 m/z= 74 m/z= 74 n= 3 n= 4 n= 5 Figure S72. MALDI-TOF MS spectrum of PDMS end-functionalized with TL9 and BzA. S60

Step-growth polymerization Synthetic procedure: In a Schlenk tube, 704 mg (0.28 mol) of PDMS-diNH 2, 100 mg (0.48 mol) of thiolactone TL 5 and 111 mg (0.19 mol) of poly(ethylene glycol) diacrylate were introduced. The reaction mixture was then stirred and heated at 50 C with a dry bath. Aliquots were taken at 15 min, 30 min, 1 h, 2 h, 4 h and 6 h to determine monomer conversion by 1 H and 31 P NMR. Number average molecular weight M n and dispersity (Ð) were determined by SEC analyses in THF. 15 15 15 15 6 14 14 1 14 14 9 3 3 1 6 8 8 9 7 5 2 4 4 2 5 7 10 11 13 11 12 13 10 CHCl 3 8, 12, 15 13 14 4 h 1 11 5, 7 2 7, 9, 10 3 6 4 15 min 0 min Figure S73. 1 H NMR spectra of the functional polymer obtained by step-growth polymerization between PDMS-diNH 2, TL5 and PEG-diacrylate at t = 0 min, 15 min and 4 h reaction time (300.13 MHz, CDCl 3,). S61

Table S1. Characterization data of PDMS-diNH 2 /TL5/PEG-diacrylate step-growth polymerization at different reaction times. Entry Reaction time (h) Conv. 1 H NMR a M n b (%) (g.mol -1 ) 1 0 7 1230-2 0.25 78 5860 1.60 3 0.5 93 7080 1.67 4 1 98 8400 1.63 5 2 98 9020 1.66 6 4 100 9120 1.66 a determined by 1 H NMR from acrylate signal, b determined by SEC analysis in THF with PS standard. Ð b S62