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N-heterocyclic carbene catalyzed addition of aldehydes to diazo compounds: stereoselective synthesis of N-acylhydrazones

N-heterocyclic carbene catalyzed addition of aldehydes to diazo compounds: stereoselective synthesis of N-acylhydrazones

Organic Letters 15(7): 1760-1763

An innovative stereoselective synthesis of N-acylhydrazones via an unprecedented N-heterocyclic carbene catalyzed addition of aldehydes to diazo compounds is presented. Enals exclusively afforded N-acylhydrazones, in yields up to 91%. The observed regioselectivity was traced back to the reaction of the vinylogous Breslow intermediate via the acyl anion pathway over competing homoenolate, enol, and acyl azolium pathways. This unusual reaction profile was studied based on DFT calculations, which revealed that the reaction is under orbital control, rather than being ruled by charge.

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Accession: 054529366

Download citation: RISBibTeXText

PMID: 23527876

DOI: 10.1021/ol400563w

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