Enantioselective organocatalytic addition of oxazolones to 1,1-bis(phenylsulfonyl)ethylene: a convenient asymmetric synthesis of quaternary alpha-amino acids.

来自 Wiley

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作者：

Andrea‐Nekane R. Alba，X Companyo，G Valero，A Moyano，R Rios

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摘要：

A new, easy, and highly enantioselective method for the synthesis of quaternary α-alkyl-α-amino acids 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-amino acid derivatives with complete C4 regioselectivity and with excellent yields and enantioselectivities. This methodology is complementary to previously reported enantioselective approaches to quaternary α-amino acids and allows the synthesis of α-phenyl-α-alkyl-α-amino acids and α- tert -butyl-α-alkyl-α-amino acids. It has distinct advantages in terms of operational simplicity, enviromentally friendly conditions, and suitability for large-scale reactions.

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关键词：

oxazole derivatives organocatalysis diastereoselective syntheses, enantioselective syntheses (incl. cis/trans‐isomerism) addition reactions

DOI：

10.1002/chem.200903025

被引量：

145

年份：

2010