Enantioselective Vinylogous Mannich Reaction of Acyclic Vinylketene Silyl Acetals with Acyclic Ketimines
K. Ogura, Tsunayoshi Takehara, Takeyuki Suzuki, Shuichi Nakamura
Abstract
Abstract The first enantioselective vinylogous Mannich reaction of acyclic vinylketene silyl acetals with acyclic ketimines derived from alkynyl ketoesters was developed. Excellent yields and enantioselectivities were obtained from the reaction using bis(imidazoline)‐Zn(II) catalyst. Based on experiments and MO calculation, a plausible transition state was proposed to explain the stereoselectivity of the reaction. The obtained products were converted into various amines and a lactam. This process provides an efficient route for the synthesis of acyclic δ‐amino‐α,β‐unsaturated carbonyl compounds and their derivatives. magnified image
Topics & Concepts
Enantioselective synthesisChemistryStereoselectivityMannich reactionSilylationAldimineCatalysisOrganic chemistryCombinatorial chemistryAsymmetric Synthesis and CatalysisSynthesis and Catalytic ReactionsSynthesis of β-Lactam Compounds