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Updated: Jul 11, 2026

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Highly selective rhodium-catalyzed conjugate addition reactions of 4-oxobutenamides
Jamie L Zigterman1, Jacqueline C S Woo, Shawn D Walker
1Chemical Process Research and Development, Amgen Inc, Thousand Oaks, CA 91320-1799, USA.
Abstract:
A variety of 4-oxobutenamides 1 were subjected to rhodium-catalyzed conjugate addition with arylboronic acids providing high regio- and enantioselectivity (97:3 to >99:1, >96% ee) and moderate to excellent yields (54-99%). The key to high selectivity is the use of sterically demanding P-chiral diphosphines, such as Tangphos or Duanphos. The product oxobutanamides 2 may be converted to alternate targets by selective derivatization of either the amide or ketone functional group. A stereochemical model predicting the absolute sense of induction was developed based on single-crystal X-ray structures of product and precatalyst.
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