Osmium-Promoted Transformation of Alkyl Nitriles to Secondary Aliphatic Amines: Scope and Mechanism
作者:Juan C. Babón、Miguel A. Esteruelas、Ana M. López、Enrique Oñate
DOI:10.1021/acs.organomet.0c00236
日期:2020.6.8
symmetrical and asymmetrical secondary aliphatic amines promoted by the hexahydride complex OsH6(PiPr3)2 (1) is described, and the mechanisms of the reactions involved are established. Complex 1 catalyzes the aforementioned transformations of aryl-, pyridyl-, and alkoxy-functionalized alkyl nitriles with linear or branched chains. The formation of the secondary amines involves primary imines, primary amines
描述了由六氢化物配合物OsH 6(P i Pr 3)2(1)促进的烷基腈向对称和不对称仲脂肪族仲胺的转化,并建立了涉及的反应机理。配合物1催化具有直链或支链的芳基,吡啶基和烷氧基官能化的烷基腈的上述转化。仲胺的形成涉及伯亚胺,伯胺和仲亚胺作为有机中间体。反应在温和的条件下(甲苯,100°C和4 bar H 2)进行。1的化学计量反应与新戊腈和2-甲氧基乙腈一起使我们能够分离三氢化物氮杂亚乙烯基衍生物OsH 3 ═N═CHR}(P i Pr 3)2(R = t Bu(3),CH 2 OMe(4))。它们的形成涉及将底物的N–C三键插入不饱和四氢化物OsH 4(P i Pr 3)2(A)的Os–H键中,这是通过从六氢化合物中消除H 2产生的前体。这些三氢化物氮杂亚乙烯基物质与H 2的反应是还原腈的N-C三键的关键步骤。在没有H 2的情况下,A对氮杂亚乙烯基配体的攻击会导致其C(sp 2)–C(sp