title: An Asymmetric Organocatalytic Quadruple Cascade to Tetraaryl-Substituted 2-Azabicyclo[3.3.0]octadienones.
abstract: A new asymmetric organocatalytic three-component quadruple cascade of α-ketoamides with α,β-unsaturated aldehydes is described. The reaction is catalyzed by the (S)-diphenylprolinol TMS ether catalyst and proceeds via an aza-Michael/aldol condensation/vinylogous Michael/aldol condensation sequence to yield tetraaryl-substituted 2-azabicyclo[3.3.0]octadienone derivatives. The cascade products are obtained with good to very good yields (34-71%), virtually complete diastereoselectivities (>20:1), and very good enantioselectivities (84-97%).
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Céline
authors.initials: C
authors.lastname: Joie
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Deckers
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Raabe
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Enders
keywords: aza-Michael addition; domino reactions; organocatalysis; quadruple cascade; vinylogous Michael addition