作者:Steven M. Allin、William R.S. Barton、W. Russell Bowman、Emma Bridge (née Mann)、Mark R.J. Elsegood、Tom McInally、Vickie McKee
DOI:10.1016/j.tet.2008.06.014
日期:2008.8
Alkyl radicals have been cyclised onto pyrroles, imidazoles and pyrazoles, and acyl radicals cyclised onto pyrroles, using Bu3SnH-, (TMS)3SiH- and Bu3GeH-mediated aromatic homolytic substitution for the synthesis of bicyclic N-heterocycles. The reactions yield intermediate π-radicals that lose hydrogen in the rearomatisation step of the aromatic homolytic substitution. Mechanistic studies of these
作者:Steven M Allin、William R.S Barton、W.Russell Bowman、Tom McInally
DOI:10.1016/s0040-4039(01)01639-2
日期:2001.10
Synthetically useful [1,2-a]-fused pyrroles, e.g. 2,3-dihydro-1H-pyrrolizidines substituted in the 1- and 7-positions, have been generated by acyl radical cyclisation onto pyrroles using N-(omega -acyl)-radicals generated front acyl-selenide precursors. The protocol does not require high pressures of CO. Mechanistic studies indicate the key role of azo radical initiators as oxidants of the intermediate pi -radicals. (C) 2001 Elsevier Science Ltd. All rights reserved.