Efficient and general conditions for the formation of stereodefined trisubstituted alkenes by using the rhodium‐catalyzed reaction of unactivated Baylis–Hillman adducts with either organoboronic acids or potassiumtrifluoro(organo)borates are reported (see scheme).
Abstract A stereospecific synthesis of enones 3 by coupling reaction of α-acetoxy alkyl methylvinylketones 2 and Gilman or Grignard reagents in the presence of a catalytic amount of copper (I) salt at low temperature, is described.