New approaches to the asymmetric synthesis of non-proteinogenic α-amino acids and dipeptides through chiral β-lactam intermediates
作者:Iwao Ojima、Hauh-Jyun C. Chen、Xiaogang Qiu
DOI:10.1016/s0040-4020(01)86038-5
日期:1988.1
Novel and effective routes to optically pure aromatic α-amino acids, α-methyl-α-amino acids and their derivatives including dipeptides are developed via homochiral β-lactams which are obtained through asymmetric [2+2] cycloadditions of ketenes to imines.
Enantioselective [3+2]-cycloaddition of 2,3-disubstituted cyclobutenones: vicinal quaternary stereocenters construction and skeletal functionalization
作者:Licheng Lu、Ping Lu
DOI:10.1039/d3sc02485g
日期:——
of complex cyclic molecules with multiple stereocenters. We report here a silver-catalyzed [3+2]-cycloaddition of 2,3-disubstituted cyclobutenones with an array of azomethine ylide precursors iminoesters, furnishing azabicycles in good yields and enantioselectivities. Up to three contiguous all-carbon quaternary centers, including two angular stereocenters, could be constructed efficiently, due to
A short and diastereoselective synthesis of newly reported aza-diketopiperazine (aza-DKP) scaffolds starting from amino-acids was achieved using domino Rh(i)-catalyzed cyclohydrocarbonylation/addition.