A new silicon lewis acid for highly enantioselective mannich reactions of aliphatic ketone-derived hydrazones

J Am Chem Soc. 2008 May 28;130(21):6676-7. doi: 10.1021/ja800830h. Epub 2008 Apr 30.

Abstract

The first general method for the highly enantioselective Mannich reaction of aliphatic ketimines is reported. A new, second generation chiral silane Lewis acid has been developed that promotes the reaction between ketone-derived hydrazones and silyl ketene acetals, providing the beta,beta-disubstituted beta-amino esters with good enantioselectivity even for the hydrazone derived from 2-butanone (methyl vs ethyl, 91% ee). Several examples are provided, including a reaction with a substituted (propanoate-derived) silyl ketene acetal.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetals / chemistry
  • Amino Acids / chemical synthesis*
  • Esters / chemical synthesis
  • Ethylenes / chemistry
  • Hydrazones / chemical synthesis
  • Hydrazones / chemistry*
  • Imines / chemistry
  • Ketones / chemistry*
  • Silanes / chemical synthesis
  • Silanes / chemistry*
  • Stereoisomerism

Substances

  • Acetals
  • Amino Acids
  • Esters
  • Ethylenes
  • Hydrazones
  • Imines
  • Ketones
  • Silanes
  • ketene