Biphenyl aldehyde-based ternary catalytic system catalyzed Tsuji–Trost allylation of N-unprotected amino acid esters
作者:Zhao-Wei Wu、Wei Wen、Qi-Xiang Guo
DOI:10.1016/j.tet.2022.133235
日期:2023.2
the direct α-allylation reaction of N-unprotected amino acid esters and allyl alcohol acetates. The chemoselectivity of C-allylation and N-allylation is efficiently controlled and various racemic α,α-disubstituted amino acid esters are generated in good-to-high yields. The target products can be readily converted into structurally diverse α,α-disubstituted amino acids at a gram scale.
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-aminoacids in moderate-to-high yields and good-to-excellent enantioselectivities. The asymmetric α-arylation reaction can be applied
A chiral aldehyde/palladium catalysis-enabled asymmetric α-allylation of NH2-unprotected amino acid esters with 1,3-disubstituted allyl acetates is described in this work. With the utilization of different chiral phosphine ligands, both the anti- and syn-selective allylation reactions are achieved enantioselectively. A series of α,α-disubstituted amino acid esters bearing two adjacent chiral centers
to manzacidins A and D, here we report a highly efficient catalyticasymmetric α-allenylic alkylation reaction of NH2-unprotected aminoacid esters that is promoted by combined chiral aldehyde/palladium catalysis. Fifty examples of unnatural α,α-disubstituted aminoacid esters are reported with good-to-excellent yields and stereoselectivities. Based on this methodology, a key intermediate leading to