title: Highly selective rhodium-catalyzed conjugate addition reactions of 4-oxobutenamides.
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.
authors.affiliation: Chemical Process Research and Development, Amgen Inc, Thousand Oaks, CA 91320-1799, USA.
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Zigterman
authors.forename: Jacqueline C S
authors.initials: JC
authors.lastname: Woo
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Walker
authors.forename: Jason S
authors.initials: JS
authors.lastname: Tedrow
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Borths
authors.forename: Emilio E
authors.initials: EE
authors.lastname: Bunel
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Faul