Journal of Organic Chemistry 2007-06-22

Design and synthesis of chiral N-chloroimidodicarbonates: application to asymmetric chlorination of silyl enol ethers.

Saumen Hajra, Manishabrata Bhowmick, Biswajit Maji, Debarshi Sinha

Index: J. Org. Chem. 72 , 4872, (2007)

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Abstract

New chiral N-chloroimidodicarbonates, which function as efficient chiral chlorinating agents, were designed and synthesized. Among these, C(2)-symmetric (1R,2S,5R)-(-)-menthyl-N-chloroimidodicarbonate 2a provided moderate to good enantioselectivity (up to 40%) for the chlorination of silyl enol ethers to afford alpha-chloroketones only in the presence of a suitable Lewis acid such as Sm(OTf)(3).