Nickel-Catalyzed Asymmetric Negishi Cross-Couplings of Secondary Allylic Chlorides With Alkylzincs

摘要

Reactions of organozinc reagents with organic halides catalyzed by nickel orpalladium via Negishi coupling have been well studied and elucidated overthe years. However, the challenge still remains to widen the applications bythe use of nucleophiles that can tolerate various functional groups in thepresence of allylic electrophiles. Using optimized conditions (Fig. 1),Negishi cross-couplings of symmetrical and unsymmetrical secondaryallylic chlorides with organozinc bromide reagents in the presence of Ni/Pybox catalyst afforded products of high enantio- and regioselectivity withyields as high as 97%.