使用PdCl(C 3 H 5)(dppb)/ KOAc催化剂,钯催化吡唑与芳基卤化物的直接芳基化反应显示出吡唑的C4和C5 C H键具有相似的反应性,而C3 C H键几乎不具有反应性,并一步一步即可获得各种4,5-二芳基吡唑类化合物。该C H键官能化反应容许芳基溴化物上的各种取代基,例如硝基,氰基,甲酰基,丙酰基,酯,氯,氟或三氟甲基。
Pd-Catalysed Direct 5-Arylation of 1-Methylpyrazole with Aryl Bromides
作者:Hamed Ammar、Henri Doucet、Anissa Beladhria、Kassem Beydoun、Ridha Salem
DOI:10.1055/s-0030-1260076
日期:2011.8
the base and DMAc as the solvent, promotes the 5-arylation in moderate to high selectivities and yields. A wide variety of aryl and heteroaryl bromide derivatives have been successfully employed. Their electronic and steric properties also have an influence on the regioselectivities and yields of the coupling products. Both electron-poor and electron-rich aryl bromides gave satisfactory results, although
Palladium-catalysed direct diarylations of pyrazoles with aryl bromides: a one step access to 4,5-diarylpyrazoles
作者:Abdelilah Takfaoui、Liqin Zhao、Rachid Touzani、Pierre H. Dixneuf、Henri Doucet
DOI:10.1016/j.tetlet.2014.01.079
日期:2014.3
The palladium-catalyseddirect arylation of pyrazoles with aryl halides, using PdCl(C3H5)(dppb)/KOAc catalyst, reveals a similar reactivity of C4 and C5 CH bonds of pyrazoles, whereas the C3 CH bond is almost unreactive, and gives access in one step to a variety of 4,5-diarylpyrazoles. This CH bond functionalisation reaction tolerates a variety of substituents on the aryl bromide such as nitro, cyano
使用PdCl(C 3 H 5)(dppb)/ KOAc催化剂,钯催化吡唑与芳基卤化物的直接芳基化反应显示出吡唑的C4和C5 C H键具有相似的反应性,而C3 C H键几乎不具有反应性,并一步一步即可获得各种4,5-二芳基吡唑类化合物。该C H键官能化反应容许芳基溴化物上的各种取代基,例如硝基,氰基,甲酰基,丙酰基,酯,氯,氟或三氟甲基。