Rhodium-catalyzed asymmetric 1,4-addition of aryl alanes to trisubstituted enones: Binap as an effective ligand in the formation of quaternary stereocenters
All for one and 1,4-all: Readily available aryl alanes are used in the rhodium-catalyzed asymmetric conjugate addition reaction with a variety of cyclic and acyclic enones. The enhanced reactivity of the system allows the use of the common binap ligand for the generation of quaternary benzylic stereocenters in excellent enantioselectivity (see scheme).
Chiral tetrafluorobenzobarrelenes as effective ligands for rhodium-catalyzed asymmetric 1,4-addition of arylboroxines to β,β-disubstituted α,β-unsaturated ketones
(Chemical Equotion Present) Lock, Stock and Two Smoking Barrelenes: The rhodium-catalyzed 1,4-addition of readily available arylboronic acid anhydrides to simple β,β-disubstituted α,βunsaturated ketones creates quaternary carbon stereocenters with high enantiomeric excesses using a chiral tetrafluorobenzobarrelene ligand.