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Provided that the correct acknowledgement is given and it is not used for commercial purposes. This article in other publications, without requesting further permission from the RSC, Guo,Ĭreative Commons Attribution-NonCommercial 3.0 Unported Licence. Based on the results given by control experiments, three reaction models are proposed to illustrate the stereoselective-control outcomes.Ĭhiral Aldehyde Catalysis Enables Direct Asymmetric α−Substitution Reaction of N-Unprotected Amino Acids with Halohydrocarbons The asymmetric α−arylation reaction can be applied in the formal synthesis of the clinical candidate compound (+)-AG-041R. By promoting a simple chiral BINOL-aldehyde catalyst or combining catalysts of a chiral aldehyde and Lewis acid ZnCl2, the asymmetric α−arylation, α−allylation, and α−benzylation of amino acid esters with the corresponding halohydrocarbons proceed smoothly, producing α,α−disubstituted α−amino acids in moderate-to-high yields and good-to-excellent enantioselectivities. Herein, we report on three highly efficient aldehyde-catalyzed direct α−hydrocarbylations of N-unprotected amino acid esters with aryl-, allyl-, and benzyl halides.

However, all the reported methodologies depend on N-unprotected amino acids as starting materials. The direct catalytic α−hydrocarbylation of readily available amino acids with halohydrocarbons is one of the most straightforward methods leading to α,α−disubstituted non-proteinogenic α−amino acid compounds.