Bu3SnH-mediated radical cyclisation onto azoles

被引：47
作者：
Allin, Steven M. [1 ]
Barton, William R. S. [1 ]
Bowman, W. Russell [1 ]
Bridge nee Mann, Emma [1 ]
Elsegood, Mark R. J. [1 ]
McInally, Tom [2 ]
McKee, Vickie [1 ]
机构：
[1] Univ Loughborough, Dept Chem, Loughborough LE11 3TU, Leics, England
[2] AstraZeneca R&D Charnwood, Loughborough LE11 5RH, Leics, England
来源：
TETRAHEDRON | 2008年 / 64卷 / 33期
基金：
英国工程与自然科学研究理事会;
关键词：
radical cyclisation; homolytic aromatic substitution; Bu3SnH; imidazole; pyrrole; pyrazole;
D O I：
10.1016/j.tet.2008.06.014
中图分类号：
O62 [有机化学];
学科分类号：
070303 ; 081704 ;
摘要：
Alkyl radicals have been cyclised onto pyrroles, imidazoles and pyrazoles, and acyl radicals cyclised onto pyrroles, using Bu3SnH-, (TMS)(3)SiH- and Bu3GeH-mediated aromatic homolytic substitution for the synthesis of bicyclic N-heterocycles. The reactions yield intermediate pi-radicals that lose hydrogen in the rearomatisation step of the aromatic homolytic substitution. Mechanistic studies of these rear-omatisation steps indicate aromatic homolytic substitution in which the initiator or breakdown products from the inhibitor are responsible for the H-abstraction step. (C) 2008 Elsevier Ltd. All rights reserved.
引用
收藏
页码：7745 / 7758
页数：14
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