The Preparation of Substituted Pyrazoles from β,β-Dibromo-enones by a Tandem Condensation/Suzuki-Miyaura Cross-Coupling Process
作者:Richard Taylor、Sandra Beltrán-Rodil、Michael Edwards、David. Pugh、Mark Reid
DOI:10.1055/s-0029-1218521
日期:2010.3
consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstituted pyrazoles from α-hydroxyketones. The first, a tandem MnO 2 -mediated oxidation/Ramirez olefination reaction, provides a facile route to β,β-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstituted pyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura
描述了从 α-羟基酮区域选择性两步合成 1,3,5-三取代吡唑的两个连续串联过程。第一个是串联 MnO 2 介导的氧化/拉米雷斯烯化反应,为 β,β-二溴烯酮提供了一条简便的途径。然后,这些有价值的 1,3-二羰基合成子可以通过第二个串联肼缩合/Suzuki-Miyaura 交叉偶联反应转化为 1,3,5-三取代的吡唑。使用这些程序,一系列芳基和烷基 α-羟基酮已被区域选择性地转化为 1,3,5-三取代的吡唑。