Homoallylic substitution reactions of lithium dialkyl cuprates with cyclopropylcarbinyl halides: mechanistic considerations

Abstract

Highly reactive lithium dialkyl cuprates and l-bromo-l-cyclo-propylalkanes, 4 , react to give good yields of the homoallylic substitution product, 6 . Less reactive organocuprates react with 4 to give mixtures of 6 and the direct substitution product, 7 . These results are consistent with a copper(I) radical intermediate which undergoes facile rearrangement prior to reductive coupling.