Cu<sup>0</sup>-Promoted Cyclisation of Unsaturated α-Halogeno Amides To Give β- and γ-Lactams
作者:Andrew J. Clark、Jonathan N. Duckmanton、Fulvia Felluga、Armando Gennaro、Franco Ghelfi、Jack R. D. Hardiman、Abdirisak A. Isse、Claudia Manferdini、Domenico Spinelli
DOI:10.1002/ejoc.201600249
日期:2016.5
Efficient 5-exo-trig atom-transfer radicalcyclisation of 13 unsaturated α-halogeno amides mediated by Cu0 (copper wire) with tripyridylmethanimine ligand (TPMA; 1 mol-%) in a mixed solvent of EtOAc/EtOH (3:1) is reported (89–98 %), with recycling of the copper wire. A substantial improvement in conversion and selectivity was obtained when Na2CO3 (5 mol-%) was added to the reaction mixture. The Cu0
Efficient β-lactam synthesis via 4-exo atom transfer radical cyclisation using CuBr(tripyridylamine) complex
作者:Andrew J Clark、Gary M Battle、Andrew Bridge
DOI:10.1016/s0040-4039(01)00737-7
日期:2001.6
The tripyridylamine copper(I) halide complex mediates the atom transfer radicalcyclisation of bromo-enamides to give β-lactams exclusively with no formation of γ-lactams. Initial products 7 arise from 4-exo bromine atom transfer but elimination can be readily achieved by reaction with DBU to furnish alkenes 8 in high yields (92–98%).