Metal-free, Mild, and Selective Synthesis of <i>Bis</i>(pyrazolyl)alkanes by Nucleophile-Catalyzed Condensation
作者:Maxym Tansky、Zipeng Gu、Robert J. Comito
DOI:10.1021/acs.joc.0c02442
日期:2021.1.15
Bis(pyrazolyl)alkanes are a prolific class of ligands for catalysis, accessible by the condensation between bis(pyrazolyl)methanones and carbonyls. In this report, we describe a nucleophile-catalyzed innovation on this condensation that avoids the transition metals, high temperatures, reagent excess, and air-sensitive reagents common among the existing protocols. Significantly, this method accommodates
双(吡唑基)烷烃是一类最多的催化配体,可通过双之间的缩合来获得(吡唑基)亚甲基和羰基。在本报告中,我们描述了这种缩合反应的亲核试剂催化创新,避免了现有协议中常见的过渡金属,高温,试剂过量和对空气敏感的试剂。重要的是,该方法可容纳空间受阻和电子形式多样的吡唑和醛,适用于系统的配体优化。此外,我们的研究范围包括以前未报道过的该反应的唑类和桥连官能团,有望用于新型杂蝎子催化剂。我们提供了难以捉摸的反应中间体的第一个直接证据,并描述了这种缩合反应的最完整机理。