Functionalization of benzylic C(sp(3))-H bonds of heteroaryl aldehydes through N-heterocyclic carbene organocatalysis.

Xingkuan Chen, Song Yang, Bao-An Song, Yonggui Robin Chi

Index: Angew. Chem. Int. Ed. Engl. 52(42) , 11134-7, (2013)

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Abstract

Aryl aldehyde activation: Oxidative activation of 2-methylindole-3-carboxaldehyde (I) through N-heterocyclic carbene (NHC) organocatalysis generates heterocyclic ortho-quinodimethane (II) as a key intermediate. This intermediate then undergoes formal [4+2] cycloaddition with trifluoromethyl ketones or isatins to form polycyclic lactones containing a quaternary carbon center. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.