3- Chloromethyl thiirane

These results suggest that poly[(chloromethyl)thiirane] (PCMT, 4) should be substantially more reactive than polyepichlorohydrin... 

Table V. Kinetics of Repeating Unit Isomerization in Poly[(chloromethyl)thiirane] and Poly(3-chlorothietane)...

Reactions of (a-chloromethyl) thiiranes with sodium phenolate in various solvents were investigated <2003RJ0226>. Reaction of 2-(chloromethyl) thiirane-3,3-42 with PhONa in 85% EtOH gave a mixture of the labeled (phenoxymethyl) thiiranes 190 and thietane 191 in 30% yield, as a 5 2 mixture of 190 191 (Scheme 44). 

In reaction of (chloromethyl) thiirane with benzimidazole 192 or with sulfonamides 193, the structures of the products formed depend on the solvent (Scheme 45) <2002RJ01507, 2005RJ01023>. 

Trifluoromethyl thiirane is formed by the action of tris(diethylamino)-phosphineon l-chloromethyl-2,2,2-trifluoroethyldisulfide [S2] (equation 73) Difluoromethyl phenyl selenide is prepared by treatment of lithium phenyl-selemde with chlorodifluoroniethane via a carbene mechanism [Si] (equation 44) Bis(2,2,2-trifluoroethyl)diselenide is formed in the reaction of 2,2,2-trifluoroethyl mesylate with lithium diselenide [84] (equation 74). 

The above explains the key roles of (a) the nucleophilicity of the nucleophile (b) the substituent(s) (c) the polarity of the reaction medium and (d) the the bulkiness of the nucleophile, in determining the regio- and stereo-specificity of the reaction. The reaction of alkyl chloromethyl ethers with thiirane oxides to give sulfenic esters128 appears to be mechanistically analogous. 

A mechanism analogous in many ways to that of the acid-catalyzed ring opening reaction was advanced for the reaction of the thiirane oxide with alkyl chloromethyl ethers S . The first step is the displacement of the chloride by the sulfoxy oxygen (equation 24). In view of the above mechanistic interpretation, it is quite surprising that the parent thiirane oxide (16a) was found to be protonated on sulfur and not at oxygen in FSOjH-SbFfi at — 78 °C, according to NMR studies s . 

A facile synthesis of 5-(2-thioxo-l,3-dithiolan-4-yl)methyl dialkylcarbamothioates and 5-thiiran-2-ylmethyl dialkylcarbamothioate from reaction of 5-(chloromethyl)-l,3-oxathiolane-2-thione with sodium dialkylcarbamodithioate and dialkylamine, respectively, has been reported to co-occur via intermolecular 0-S rearrangement (Scheme 81). " ... 

Alkyl chloromethyl ethers react with thiiran 1-oxide to give sulphenic esters (26), probably by way of an intermediate sulphoxonium salt (27). Thiiran oxide in FSOsH-SbF at — 78 C was protonated at sulphur and not at oxygen, according to n.m.r. studies. ... 

Thiirane 1-oxide added to a soln. of chloromethyl /i-propyl ether in abs. methylene chloride, and stirred 12 hrs. under anhydrous conditions -> -propoxy-methyl 2-chlorethanesulfenate. Y 70%. F. e. s. E. Vilsmaier and B. Hloch, Synthesis 1971, 590. 

The initiator system 2a/DBU was formed by addition of DBU ([2a]/[DBU] = 1 1), which leads to the thiolate/thiol equilibrium through proton exchange The polymerization of MT using this initiator system was carried out in DMF at 0 °C and was quenched by l-(chloromethyl)naphthalene, which has been reported to be effective for termination of thiirane polymerization. With a feed ratio of [MT]o/[2a/DBU]o = 30, the reartion was complete within 5 min to afford the corresponding star-shaped polymer the nrrmber-average molecular weight (M ) and MWD (Mw/MJ, which were 3500 and 1.05, respectively. 

Thiocyanate ion can cause isomerization of thiirans. The reactivity of 2-methylthiiran to hydrochloric acid has been compared with the reactivities of 2-methyloxiran, 2-methylaziridine, and methylcyclopropane. Treatment of 2-chloromethyl- and 2-alkoxymethyl-thiirans with aqueous chlorine yields the corresponding 1,3-dichloropropane- or l-alkoxy-3-chloro-2-sulphonyl chlorides. Hydrochloric acid alone yields the 2-thiol. Nucleophilic attack on the sulphur atom of 2-bromomethylthiiran by potassium thiobutoxide yields the disulphide (60). Attack by the sulphur atom of 2-methylthiiran on benzoyl isocyanate (61) yields a mixture believed to contain (62). ... 

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