Journal of Organic Chemistry 2003-12-12

Novel synthesis of conjugated dienes attached to a quaternary carbon center via Pd(0)-catalyzed deconjugative allylation of alkenylidenemalonates.

Yoshihiro Sato, Yoshihiro Oonishi, Miwako Mori

Index: J. Org. Chem. 68(25) , 9858-60, (2003)

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Abstract

Palladium(0)-catalyzed deconjugative allylation of alkenylidenemalonates and alkylidenemalonates was achieved for the first time. Reactions of dimethyl 2-((E)-but-2-enylidene)malonate with various allylic acetates using LHMDS as a base in DMF in the presence of Pd(2)dba(3) (2.5 mol %) and PPh(3) (10 mol %) proceeded at room temperature to give the corresponding alpha-allylation products in good yields in a regio- and stereoselective manner. This reaction can also be used for allylation of dimethyl ethylidenemalonate or dimethyl 2-((E)-pent-2-enylidene)malonate and give the desired alpha-allylation products in good yields.