N-(2-Hydroxyacetyl)pyrrole as an Ester Surrogate in Asymmetric Mannich Reactions
S. Harada, S. Handa, S. Matsunaga, M. Shibasaki*
University of Tokyo, Japan
21 September 2005 (online)
N-(2-Hydroxyacetyl)pyrrole underwent a direct Mannich reaction with a variety of o-Ts aldimines to afford predominantly a syn-α-hydroxy-β-amino amide in good to excellent yield. Good diastereoselectivity and high enantionselectivity were achieved by using In(Oi-Pr)3 and (S,S)-linked BINOL as the catalyst system. Chiral aminoalcohols are important building blocks for many natural products and pharmaceuticals. As an ester equivalent, the N-acyl amide can be easily transformed to many common functional groups such as esters, alkyl amides, aldehydes.