Studies on Ring—Opening Polymerization of Chloromethyl Thiirane with Rare Earth Catalysts and Functional Resins Synthesized therewith

Studies on ring-opening polymerization of chloromethyl thiirane with rare earth catalysts and functional resins synthesized therewith were reviewed.     

SOLVENT-FREE CONVERSION OF OXIRANES TO THIIRANES WITH THIOUREA

A simple and efficient method for the conversion of various oxiranes to the corresponding thiiranes using thiourea under solvent free conditions is described.     

Silica Chloride–Catalyzed Synthesis of Thiiranes from Oxiranes Under Solvent-Free Conditions

A mild, simple, and efficient method for the synthesis of thiiranes from epoxides using a catalytic amount of silica chloride under solvent-free conditions has been developed. Experimental simplicity, simple work-up procedure, and solvent-free reaction conditions are important features of the present protocol.     

Conversion of Oxiranes to Thiiranes Catalyzed with Silica Gel–Supported Aluminium Chloride

Silica gel–supported aluminium chloride, SiO₂‐AlCl₃, catalysizes the efficient conversion of different oxiranes to their corresponding thiiranes in the presence of thiourea under nonaqueous conditions.     

Ring-opening Polymerization of Chloromethyl Thiirane with Catalytic Systems Composed of Lanthanide Compound and Ethyl Aluminum Sesquichloride

Thering-openingpolymerinahonofchloromethylthiirane(CMT)wasfirstcatriedoutinl952.lLater,itwasfoundthatcahoniccatalystSH,SO','CF3SO3H,andBF,.OEt2'couldpolymerizeCMTbutwithoutdefndtedataofmolecularweightandcatalghcefficiency.Anioincinihators,suchasKOHandNaNH2,areineffechve.2OrganocomPoundsbasedoncadminIn,zinc,andaluIninmcanconvertCMTtoviscousoil.2TwocomPonentZiegler-NattampecatalystsbasedonneodyIninmtris(2-ethylhexylphosphonate),Nd(Pzoo)s,andtriisobutylaluIninUmeAlitedhighactivity…     

A Green Protocol for Solvent-Free Conversion of Epoxides to Thiiranes with Dowex-50WX8–Supported Thiourea

Structurally different epoxides were efficiently converted to the corresponding thiiranes by Dowex-50WX8–supported thiourea under solvent-free conditions. The reactions were carried out either in an oil bath or under microwave irradiation to give the thiiranes in 75–98% yields within 30 sec–120 min.     

FORMATION AND GC-MS CHARACTERIZATION OF UNUSUAL CYCLIC SULFIDES

Abstract

connection with another project involving the cleavage of the thiirane ring of cyclohexene episulfide in the presence of trifluoromethylthiocopper, the presence of several unusual cyclic sulfides (5–10, Fig. 1) was observed both in the reaction product and the starting material itself. The formation of these compounds has been rationalized on the presence and participation of the thiyl radical species. Details pertaining to their formation and characterization based on their mass spectral fragmentation behavior are presented in this communication.     

Controlled ring‐expansion polymerization of thiiranes based on cyclic aromatic thiourethane initiator

Ring‐expansion polymerization (REP) of thiiranes was investigated using 3H‐benzothiazol‐2‐one (BT) as the cyclic aromatic thiourethane initiator in the presence of tetrabutylammonium chloride (TBAC) catalyst. The polymerization proceeded in a well‐controlled manner to afford cyclic polysulfides with one BT moiety per macrocycle, as confirmed by MALDI‐TOF MS spectroscopy. Differential scanning calorimetry (DSC) measurement of the obtained cyclic polysulfides revealed slight decrease in the glass‐transition temperature as the increase in the molecular weight, supporting the cyclic topology of the products. Postpolymerization of thiiranes using the BT‐initiated cyclic polysulfide as the macroinitiator afforded the ring‐expanded product while maintaining the narrow polydispersity and well‐defined cyclic structure, which enabled precise synthesis of cyclic block copolymer with different thiirane combination. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2442–2449     

Synthesis of refractive star‐shaped polysulfide by anionic polymerization of phenoxy propylene sulfide using an initiating system consisting of trifunctional thiol derived from five‐membered cyclic dithiocarbonate and amine

Star‐shaped poly(phenoxy propylene sulfide) [poly (PPS)] were synthesized by anionic polymerization using a trifunctional initiator ( I ₁) derived from a trifunctional five‐membered cyclic dithiocarbonate and benzyl amine. Conditions for the anionic polymerization of PPS were optimized to obtain polymers with desired M_ns and narrow M_w/M_ns. The best catalyst and solvent were DBU and DMF, respectively. The star‐shaped structure of the resulting star poly(PPS) was supported by SEC analysis. The refractive indexes (n_D) of the star poly (PPS) were relatively high (>1.64). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 525–531, 2010     

Enantiomer‐selective polymerization of (RS)‐(phenoxymethyl)thiirane with diethylzinc/L‐amino acid

Enantiomer‐selective polymerization of (RS)‐(phenoxymethyl)thiirane (RS‐ 1 ) was carried out with ZnEt₂/L ‐α‐amino acid as an initiator system, and the effect of the initiator system on the enantiomer selectivity was examined with various amino acids. All polymerizations heterogeneously proceeded, and every initiating system was effective in producing optically active polymers. For the polymerization of RS‐ 1 with diethylzinc (ZnEt₂)/L ‐leucine (1/1), the conversion was 43.7% in 12 days, and the number‐average molecular weight of the polymer was 18,000. The enantiomer selectivity was maximum when the molar ratio of the two components in the ZnEt₂/L ‐α‐amino acid system was 1:1. When the ZnEt₂/L ‐leucine (1/1) system was used in the polymerization, the best result was obtained with an enantiomer‐selectivity value of 5.36. During the polymerization, the S enantiomer was preferentially consumed, and the isotactic‐rich polymer was enriched in the S configurational units produced. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3443–3448, 2002