SYNTHESIS, REACTIONS, AND INTERCONVERSIONS OF SOME 2-(TRIMETHYLSILYL)ETHYL SUBSTITUTED SULFUR-COMPOUNDS

In an effort to probe the compatibility of the 2-(trimethylsilyl)ethyl sulfur moiety with standard organosulfur transformations, several 2-( trimethylsilyl)ethanethiol derivatives have been prepared in excellent yield. Thus 2-(trimethylsilyl)ethanethiol (1) and 2-(trimethylsilyl)e thyl disulfide (4) and its corresponding thiosulfinate 9 and thiosulfo nate 10 have been synthesized. One method of formation of 4 involves t he breakdown of a 1-(trimethylsilyl)ethyl unit while the 2-(trimethyls ilyl)ethyl fragment survives. Oxidation of 4 or 9 to 10 did not procee d efficiently with common reagents, but proceeded well with an iodine/ water system. 2-(Trimethylsilyl)ethyl sulfide (11a) and its oxides (13 , 14) were also prepared in good yield. Sulfoxide 13 and 2-(trimethyls ilyl)ethyl tert-butyl sulfoxide 15 were shown to be good precursors to 2-(trimethylsilyl)ethanesulfinyl chloride (16). (Trimethylsilyl)methy l sulfine reacted with 16 in an inefficient manner to give thiosulfona tes 10, 19, and 20. 2-(Trimethylsilyl)ethanesulfenyl chloride could be generated and captured by addition across cyclohexene. The reaction o f thiosulfinate 9 with several thiosilanes is an excellent method for the synthesis of 2-(trimethylsilyl)ethyl containing mixed disulfides.