Asymmetric Synthesis of alpha-Allyl-alpha-Aryl alpha-Amino Acids by Tandem Alkylation/pi-Allylation of alpha-Iminoesters

作者:Curto John M; Dickstein Joshua S; Berritt Simon; Kozlowski Marisa C*
来源:Organic Letters, 2014, 16(7): 1948-1951.
DOI:10.1021/ol500506t

摘要

The first asymmetric synthesis of alpha-allyl-alpha-aryl alpha-amino acids by means of a three-component coupling of alpha-iminoesters, Grignard reagents, and cinnamyl acetate is reported. Notably, the enolate from the tandem process provides a much higher level of reactivity and selectivity than the same enolate generated via direct deprotonation, presumably due to differences in the solvation/aggregation state. A novel method for removal of a homoallylic amine protecting group delivers the free amine congeners. The alpha-allyl group offers a means to generate further valuable alpha-amino acid structures as exemplified by ring closing metathesis to generate a higher ring homologue of alpha-aryl-proline.

  • 出版日期2014-4-4