Enantioselective Organocatalytic Addition of Oxazolones to 1,1-Bis(phenylsulfonyl)ethylene: A Convenient Asymmetric Synthesis of Quaternary α-Amino Acids
作者:Andrea-Nekane R. Alba、Xavier Companyó、Guillem Valero、Albert Moyano、Ramon Rios
DOI:10.1002/chem.200903025
日期:2010.5.10
A new, easy, and highlyenantioselective method for the synthesis of quaternary α‐alkyl‐α‐aminoacids based on organocatalysis is reported. The addition of oxazolones to 1,1‐bis(phenylsulfonyl)ethylene is efficiently catalyzed by simple chiral bases or thioureas. The reaction affords α,α‐disubstituted α‐aminoacid derivatives with complete C4 regioselectivity and with excellent yields and enantioselectivities