P Toluenesulfenyl chloride

In contrast to benzyl p-tolyl sulfoxide 37, allyl p-tolyl sulfoxide 217 racemizes between 50 and 70°C. The values of the activation energy and the entropy (A/f = 23 kcal/mol AS = -4.9 e.u.) as well as the absence of decomposition products are indicative of a different racemization mechanism for this sulfoxide. In this connection, it is interesting to note that the condensation of p-toluenesulfenyl chloride with allyl alcohol labeled in the a-position with deuterium... 

The concept of stereocontrol by the ion pan mechanism in the electrophilic additions of sulfenyl chlorides has been further discussed - by Zeflrov, using norbornadiene (49) as a substrate. The addition of sulfenyl chlorides to 49 has been reported to give a product distribution markedly dependent on the sulfenylating agent. In particular, it has been observed s addition of p-toluenesulfenyl chloride gives only the anti 1,2-... 

Sulfuryl chloride also chlorinates arenes in the nucleus if silica gel is present in small amounts. Silica gel is also a satisfactory catalyst for condensation of arenes with p-toluenesulfenyl chloride, TsSCl, and CeHs SCH2C1. ... 

Butyllithium in hexane added dropwise at -20° under Ng to a soln. of methallyl alcohol in anhydrous tetrahydrofuran, then p-toluenesulfenyl chloride in tetra-hydrofuran added dropwise, warmed to room temp., and the product isolated after 15 min. -> methallyl p-tolyl sulfoxide. Y 92%. P. A. Grieco and R. S. Finkelhor, J. Org. Chem. 38, 2245 (1973). 

A soln. of methyl vinyl ether in methylene chloride added under argon to a soln. of /7-toluenesulfenyl chloride in the same solvent at —70°, treated with TiCl4 in methylene chloride for 5 min, a soln. of methoxyallene added, left for 1 h at the same temp., and poured into satd. NaHC03/ice with vigorous stirring -> product. Y 66%. F.e.s. I.P. Smolyakova, V.A. Smit, Izv. Akad. Nauk SSSR Ser. Khim. 1988, 2792-6. 

Concurrent with the above, a group at the Squibb Institute (Gordon et al., 1977, 1980) independently reported a different approach to 7(6)-a-methoxylation of p-lactams, which also relied upon sulfenimines as key intermediates. These workers found that reaction of amine esters with 3 equiv of toluenesulfenyl chloride or methylsulfenyl chloride in methylene chloride containing propylene oxide-molecular sieves to act as an acid scavenger, afforded sulfenimines 230-232 in about 80% yield. This reaction presumably proceeds by successive sulfenylation of amine... 

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