Metal-free cross-dehydrogenative C–N coupling of azoles with xanthenes and related activated arylmethylenes
摘要:
A metal-free C(sp(3))-H/N-H cross-coupling of azoles with xanthenes and related activated arylmethylenes is presented. Both the use of azoles and the activation pattern of C(sp(3))-H sources are essential for this transformation. In the presence of 2.0 equiv of benzoyl peroxide (BPO), methylenes bearing a heteroatom-bridged bisaryl group reacted with various azolic N-H sources to afford C-N bond forming products in usually excellent or quantitative yields, and the diphenylmethane and methylenes coactivated by a phenyl group and an adjacent heteroatom are less reactive. Mechanistic investigations suggest that a radical/radical cross-coupling pathway might be involved.[GRAPHICS].
Construction of 3-aryl-1,2,4-benzotriazines via unprecedented rearrangement of bis(benzotriazol-1-yl)methylarenes
作者:Zhiyun Zhong、Ran Hong、Xiaoxia Wang
DOI:10.1016/j.tetlet.2010.10.093
日期:2010.12
3-Aryl-1,2,4-benzotriazines were formed unexpectedly by the treatment of 1,l-bis(benzotriazol-1-yl) methylarenes with allylsamarium bromide. A radical pathway was proposed involving steps, such as fragmentation, ring-opening, and cyclization. (C) 2010 Elsevier Ltd. All rights reserved.