Palladium-Catalysed Regioselective Sequential C-5 and C-2 Direct Arylations of 3-Acetylpyrroles with Aryl Bromides
作者:Yijing Xu、Liqin Zhao、Yiqun Li、Henri Doucet
DOI:10.1002/adsc.201300123
日期:2013.5.3
to be effective for the direct regioselective C‐5 arylation of 3‐acetylpyrroles with ortho‐substituted aryl bromides. This procedure has been found to be tolerant to a variety of functional groups at C‐2 of the aryl bromide such as methyl, formyl, nitrile, nitro, hydroxymethyl, chloro, fluoro or trifluoromethyl. The sequential direct C‐5 arylation followed by C‐2 arylation of such 3‐substituted pyrroles
发现PdCl(C 3 H 5)(dppb)/ KOAc系统对于3-乙酰基吡咯与邻位取代的芳基溴化物的直接区域选择性C-5芳基化有效。已发现此方法可耐受芳基溴化物C-2上的各种官能团,例如甲基,甲酰基,腈,硝基,羟甲基,氯,氟或三氟甲基。依次直接进行C-5芳基化,然后再进行此类3-取代吡咯的C-2芳基化,可以高产率地合成2,5-二芳基-3-乙酰基吡咯。