Novel and versatile methodology for synthesis of cyclic imides and evaluation of their cytotoxic, DNA binding, apoptotic inducing activities and molecular modeling study
作者:Alaa A.-M. Abdel-Aziz
DOI:10.1016/j.ejmech.2006.12.003
日期:2007.5
developed for synthesis of N-substituted imides. Thus, acid anhydrides, imides and dicarboxylic acids were successfully subjected to dehydrative cyclization with substituted amines using DPPOx and Et(3)N to afford N-substituted imides under mild conditions. The DNA binding and apoptosis induction were investigated with regard to their potential utility as cytotoxic agents. Molecular modeling methods
Efficient conversion of acids and esters to amides and transamidation of primary amides using OSU-6
作者:Baskar Nammalwar、Nagendra Prasad Muddala、Field M. Watts、Richard A. Bunce
DOI:10.1016/j.tet.2015.10.016
日期:2015.12
with strong Bronsted acid properties, has been used to promote the high-yield conversion of carboxylic acids and esters to carboxamides as well as transamidations of primary amides in a one-pot solventless approach. A metal-free heterogeneous catalyst that promotes all of these processes has not been previously reported. OSU-6 enables these transformations to proceed in shorter times and at lower temperatures
Bismuth(III) triflate was found to promote the formation of stable cyclic N-acyliminium species in remarkable catalytic amounts (1 mol %). The alpha-amidoalkylation process seems to be effective in intermolecular and intramolecular manners leading to alpha-substituted lactams and heterocyclic systems containing azacycles, respectively. By comparing our results with those obtained with the classical Lewis acids as catalysts, it was evidenced clearly that the use of bismuth(III) triflate had been efficient for nearly all alpha-acetoxy lactams we used, except for N-acyliminium precursors bearing a sulfur atom. Also, the process seems to be easy, general, and clean, having diastereoselectivity comparable to protocols using classical Lewis acids and resulting in the formation of polyheterocyclic systems in good to excellent yields (64-99% in acetonitrile as solvent).