清华大学刘强团队报道了锰氢化物酰胺化配合物的结构、反应活性及催化性能。相关研究成果发表在2022年9月12日出版的《自然化学》。

广泛应用的Noyori型氢化催化剂的高效性源于与金属中心配位的N–H部分，其通过氢键相互作用稳定了决定速率的过渡状态。有人提出，通过使用过量的金属醇盐（M′或）取代N-H部分的N-M′基团（M′=碱金属）可以实现更高的效率；然而，尚未分离出这种金属氢化物酰胺中间体。

该文介绍了金属氢化物-酰胺络合物（HMn-NLi）的合成、分离和反应性。动力学研究表明，氢化物从HMn–NLi转移到酮的速率比相应的氨基金属氢化物络合物（HMn–NH）高24倍。此外，使用HMn–NLi作为活性催化剂实现了N-烷基取代的醛亚胺的氢化，而HMn–NH的效果要差得多。这些结果强调了M/NM′双功能催化在氢化反应中优于经典的M/NH双功能催化剂。

附：英文原文

Title: Structure, reactivity and catalytic properties of manganese-hydride amidate complexes

Author: Wang, Yujie, Liu, Shihan, Yang, Haobo, Li, Hengxu, Lan, Yu, Liu, Qiang

Issue&Volume: 2022-09-12

Abstract: The high efficiency of widely applied Noyori-type hydrogenation catalysts arises from the N–H moiety coordinated to a metal centre, which stabilizes rate-determining transition states through hydrogen-bonding interactions. It was proposed that a higher efficiency could be achieved by substituting an N–M′ group (M′=alkali metals) for the N–H moiety using a large excess of metal alkoxides (M′OR); however, such a metal-hydride amidate intermediate has not yet been isolated. Here we present the synthesis, isolation and reactivity of a metal-hydride amidate complex (HMn–NLi). Kinetic studies show that the rate of hydride transfer from HMn–NLi to a ketone is 24-fold higher than that of the corresponding amino metal-hydride complex (HMn–NH). Moreover, the hydrogenation of N-alkyl-substituted aldimines was realized using HMn–NLi as the active catalyst, whereas HMn–NH is much less effective. These results highlight the superiority of M/NM′ bifunctional catalysis over the classic M/NH bifunctional catalysis for hydrogenation reactions.

DOI: 10.1038/s41557-022-01036-6

Source: https://www.nature.com/articles/s41557-022-01036-6