Regioselective Rapid Analogue Syntheses of 1-Methyl-3,5-diarylpyrazoles via Palladium-catalysed Coupling to 3(5)-Pyrazolyl Nonaflates
作者:Ian Collins、Sylvie Bourrain、Mark Ridgill
DOI:10.1055/s-2004-820020
日期:——
Regioselective rapid analogue syntheses of 1-methyl-3,5-diarylpyrazoles were developed, based on Pd-catalysed couplings to 1-methyl-3(5)-arylpyrazole nonaflates, which offered an advantage in hydrolytic stability over the corresponding triflates. The new bifunctional reagent 1-methyl-3-bromo-pyrazol-5-yl nonaflate underwent highly chemoselective Pd-catalysed couplings to the nonaflate, followed by Suzuki couplings to the bromide, allowing sequential, regioselective introduction of the two aryl substituents.
基于 1-甲基-3(5)-芳基吡唑壬酸酯与 1-甲基-3(5)-芳基吡唑壬酸酯的钯催化偶联反应,开发了 1-甲基-3,5-二芳基吡唑的区域选择性快速类似物合成方法。新的双功能试剂 1-甲基-3-溴吡唑-5-基壬酸酯在 Pd 催化下与壬酸酯发生高化学选择性偶联反应,然后与溴化物发生铃木偶联反应,从而顺序、区域选择性地引入两个芳基取代基。