1,1,3,3-tetramethyldisiloxane: a versatile reducing agent
Some recent applications of several highly useful reducing capabilities of tetramethyldisiloxane, TMDS, are reviewed.
The hydride of organosilanes has been employed in the reductions of a vast array of organic substrates oftentimes with excellent chemoselectivity. This high degree of chemoselectivity can be credited to the weakly hydridic character of the Si-H bond along with the large variation in catalytic protocols available to carry out the reductions. A comprehensive review of the ionic and transition metal-catalyzed silane reductions has been published (1). In addition to the potential for high selectivity via the weakly hydridic silanes the organosilane reducing agents are available in a variety of forms including the popular and easily handled triethylsilane, the more sterically demanding triisopropylsilane, the specialty phenylsilane, and, finally, the more economical polymethylhydrogen siloxanes, PMHS. Sym-tetramethyldisiloxane, TMDS, has recently been shown to bring about several interesting and highly useful reductions, some of which are presented herein.
THE REDUCTION OF AMIDES TO AMINES
The reduction of amides to amines, a transformation traditionally carried out with borane or a borane derivative, can be nicel ...