B-Alkylcatecholboranes as a Source of Radicals for Efficient Conjugate Additions­ and Allylations

Abstract

B-Alkylcatecholboranes, easily prepared in situ by hydroboration of alkenes, are powerful radical precursors that can be used for carbon-carbon bond formation. Typical procedures for (a) conjugate addition to enones, (b) conjugate addition to activated alkenes such as vinyl sulfones, and (c) direct allylation are described. Experimentally, these three one-pot reactions are easy to perform. No slow addition of a reagent, a procedure frequently encountered in intermolecular radical additions, is required.

Key words

radicals - tin-free - hydroboration - allylation - conjugate addition

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