Copper(I) tert-butoxide-promoted 1,4 Csp-to-O silyl migration: Generation of vinyl copper equivalents and their stereospecific cross-coupling with allylic, aryl, and vinylic halides
Successive treatment of the (Z)-γ-trimethylsilyl allylic alcohols with 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 vinylic halides in the presence of palladium(O) catalyst gave the corresponding cross-coupling products in good yields. The stereoselective preparation of the starting materials is also described.
Formula presented The cyclic silyl ethers, 2,2-dimethyl-1-oxa-2-sila-3-cyclopentenes, were produced by the treatment of (Z)-γ-trimethylsilyl allylic alcohols with a catalytic or stoichiometric amount of lithium tert-butoxide. On the other hand, successive