Enantioselective Synthesis of Cyclopentene Carbaldehydes by a Direct Multicatalytic Cascade Sequence: Carbocyclization of Aldehydes with Alkynes
作者:Kim L. Jensen、Patrick T. Franke、Carlos Arróniz、Sara Kobbelgaard、Karl Anker Jørgensen
DOI:10.1002/chem.200903405
日期:2010.2.8
A multicatalytic, asymmetric cascade reaction sequence of α,β‐unsaturated aldehydes with alkyne‐tethered nucleophiles has been developed. Organocatalytic iminium–enamine catalysis combined with Lewis acid alkyne activation gave cyclopentenecarbaldehyde products in good yields and excellent stereoselectivities (see scheme). To highlight the potential of the sequence, a key structure for the preparation