Stereospecific alkylation of (Z)-β-hydroxymethylvinylsilanes proceeded by treatment with copper(I) tert-butoxide and alkyl halides. Tri- and tetra-substituted allylic alcohols were obtained with complete retention of configuration.
[GRAPHICS]The cyclic silyl ethers, 2,2-dimethyl-1-oxa-2-slia-3-cyclopentenes, were produced by the treatment of (2)-gamma -trimethylsilyl allylic alcohols with a catalytic or stoichiometric amount of lithium tort-butoxide. On the other hand, successive treatment of the alcohols with copper(l) tert-butoxide and allylic halides followed by the tetrabutylammmonium fluoride assisted hydrolysis produced the allylation products, 2,5-alkadien-1-ols, with complete retention of configuration of the double bond.
Copper(I) <i>tert</i>-Butoxide-Promoted 1,4 C<sup>sp</sup><sup><sup>2</sup></sup>-to-O Silyl Migration: Generation of Vinyl Copper Equivalents and Their Stereospecific Cross-Coupling with Allylic, Aryl, and Vinylic Halides
copper(I) tert-butoxide and allylic halides followed by the tetrabutylammonium fluoride-assisted hydrolysis produced the allylation products, 2,5-alkadien-1-ols, with complete retention of configuration. Similar treatment of the organometallic intermediates with aryl and vinylichalides in the presence of palladium(0) catalyst gave the corresponding cross-coupling products in good yields. The stereoselective