Enantioselective Organocatalytic Enamine C−H Oxidation/Diels‐ Alder Reaction

Abstract

α,β‐unsaturated aldehydes have been traditionally used in LUMO lowering asymmetric aminocatalysis (iminium catalysis), while the use of saturated aldehydes as substrates in this type of catalysis has been elusive, until recently. Herein, we demonstrate that organic, single‐electron oxidants in the presence of diarylprolinol silylether type catalysts serve as effective tools for the transformation of electron rich enamines to iminium ions which partake in a subsequent Diels‐Alder reaction. This enantioselective one‐pot transformation represents the first example of saturated aldehydes being used in domino Diels‐Alder reaction processes and demonstrates the power of this protocol for construction of stereo‐defined chiral compounds and building blocks.