β-Amino acid N-carboxy anhydrides (β-NCAs) are rarely used in the synthesis of β-peptides, which is due mainly to the poor availability of these potentially useful substrates. Herein, we describe the heretofore challenging synthesis of β-NCAs via a single-step, rapid, and mild formation using pH flash switching and flash dilution, which are aspects of micro-flow technology. We synthesized 15 β-NCAs
Preparation of Lactams from Cyclic Anhydrides via N‐Carboxyanhydride Intermediates
作者:Simon N. Smith、Stephen J. Connon
DOI:10.1002/ejoc.202100751
日期:2021.10.26
Cyclic anhydrides can be readily converted to ring-contracted lactams after sequential silylazidation, protonolysis, Curtius rearrangement and catalysis of ring closure by DMAP, in an operationally simple procedure. Succinic anhydrides do not form ring-contracted β-lactams but instead generate β-N-carboxyanhydrides which serve as activated analogues of β-amino acids of use in β-peptide and polymer