Ligand-Controlled Synthesis of Azoles via Ir-Catalyzed Reactions of Sulfoxonium Ylides with 2-Amino Heterocycles
作者:Alicia M. Phelps、Vincent S. Chan、José G. Napolitano、Scott W. Krabbe、Jennifer M. Schomaker、Shashank Shekhar
DOI:10.1021/acs.joc.6b00497
日期:2016.5.20
developed for the synthesis of imidazo-fused pyrrolopyrazines. The presence or absence of a nitrogenated ligand controlled the outcome of the reaction, leading to simple β-keto amine products in the absence of added ligand and the cyclized 7- and 8-substituted-imidazo[1,2-a]pyrrolo[2,3-e]pyrazine products in the presence of ligand. This catalyst control was conserved across a variety of ylide and amine coupling
开发了一种铱催化的方法,用于合成咪唑并稠合的吡咯并吡嗪。氮化配体的存在与否控制反应的结果,在不存在配体和环化的7和8位取代的咪唑并[1,2 -a ]吡咯并[2]的情况下,生成简单的β-酮胺产物,3 -e]吡嗪产物在配体存在下。在各种内酰胺和胺偶合伙伴中,这种催化剂的控制是保守的。通过NMR光谱显示,在没有其他配体的情况下,底物充当铱催化剂的配体。动力学研究表明,Ir-卡宾的形成是可逆的,并且反应缓慢。这些机理研究表明,β-酮胺产物是通过分子内卡宾N–H插入形成的,而咪唑并吡咯并吡嗪是通过分子间卡宾N–H插入形成的。