copper(I) Species: Versatile Reagents To Prepare Functionally Substituted Allylic Silanes

Article abstract of DOI:10.1021/jo00225a033

Smooth S_N2' reactions in α-alkynyl and -allenyl oxiranes, in esters derived from α-allenic alcohols, and in the bis(methanesulfonate) derived from 1,4-dihydroxy-2-butyne were observed with the reagent <(trimethylsilyl)methyl>copper(I).In this way, several allylic silanes bearing functional groups became available.Another route to functionally substituted allylic silanes was elaborated by adding <(trimethylsilyl)methyl>copper(I) or its homocuprate derivative to alkynes such as 2-alkynoic esters, ethoxyacetylene, 1-alkynyl sulfides, and 1-alkynyl sulfones.The addition reactions appeared to occur regiospecifically and in many cases also with high stereoselectivity.A 1,4-bis<(trimethylsilyl)methyl>-substituted butatriene derivative could be obtained by sequential addition of the bis<(trimethylsilyl)methyl>cuprate compound and methyl iodide to a 1-alkynyl sulfide.For one case it was shown that the addition of <(trimethylsilyl)methyl>copper(I) to 1-alkynyl sulfones can be used to prepare sulfur-free 1-alkenes bearing in the β-position the (trimethylsilyl)methyl group.