A variety of 4-oxobutenamides 1 were subjected to rhodium-catalyzed conjugate addition with arylboronicacids providing high regio- and enantioselectivity (97:3 to >99:1, >96% ee) and moderate to excellentyields (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 byselective derivatization of either the amide or ketone functional group. A stereochemical model predictingthe absolute sense of induction was developed based on single-crystal X-ray structures of product andprecatalyst.
