构建模块化催化体系用于氢转移反应:氢键的促进作用  

Construction of modularized catalytic system for transfer hydrogenation:Promotion effect of hydrogen bonds

作　　者：刘鑫[1,3] 王茂弟 任亦起 刘嘉立 戴慧聪 杨启华 Xin Liu;Maodi Wang;Yiqi Ren;Jiali Liu;Huicong Dai;Qihua Yang(State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China;Key Laboratory of the Ministry of Education for Advanced Catalysis Materials,Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces,Institute of Physical Chemistry,Zhejiang Normal University,Jinhua 321004,Zhejiang,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室,辽宁大连116023 [2]浙江师范大学化学与材料科学学院先进催化材料教育部重点实验室,固体表面反应化学省重点实验室,浙江金华321004 [3]中国科学院大学,北京100049

出　　处：《Chinese Journal of Catalysis》2023年第9期207-216,共10页催化学报（英文）

基　　金：国家自然科学基金(22272164,21972134);浙江省创新创业领军人才引进项目(2022R01007).

摘　　要：酶是一种高效的生物催化剂,它可以通过多个活性位点的协同催化,在温和反应条件下显示出高活性和高选择性.受酶催化机理的启发,合理设计具有特定活性位点的类酶催化剂来稳定过渡态,降低反应能垒并提高反应速率是实现高效绿色化学转化的一种有前景的策略.迄今为止,研究人员已经开发了多种材料来制备具有模拟酶功能的仿生催化剂,如胶束和囊泡等软材料、介孔二氧化硅和金属有机框架材料(MOFs)等.虽然上述材料具有灵活可调的活性位点和易于修饰的多孔结构等优点,但在一种催化剂中实现多个活性位点的整合依然面临巨大挑战,特别是在不同活性位点共存的条件下如何保持互不干扰以及不相容基团的兼容性等一系列问题.模块化是一种将复杂的体系分解成各种可操作的子模块的方法,每个子模块之间相互独立,但又以一定的方式进行相互协作.因此,构建模块化的催化体系来模拟酶的协同催化模式是一种有效途径.本文报道了一种将不同活性位点组合在一起的简便方法,即通过共价有机框架材料(COFs)和Cu_(2)Cr_(2)O_(5)共同构建一种具有协同效应的模块化催化体系,其中COFs和Cu_(2)Cr_(2)O_(5)分别模拟酶中的氨基酸官能团和活性位点.在肉桂醛的氢转移反应中,该模块化催化体系具有较好的催化性能,对理想产物肉桂醇的选择性>99%,并且反应速率是Cu_(2)Cr_(2)O_(5)的4倍以上.此外,活化能的测定结果表明,模块化催化体系COFs-Cu_(2)Cr_(2)O_(5)的表观活化能远低于Cu_(2)Cr_(2)O_(5),说明了COFs的存在能够显著降低肉桂醛氢转移反应能垒,从而提高模块化催化体系在该反应中的催化活性.为进一步探究COFs在上述反应中的作用,进行了一系列机理研究.结果表明,模块化催化体系中COFs与异丙醇通过氢键相互作用,进而促进异丙醇发生脱氢反应和氢原子在异丙醇和肉桂醛之间的转�The construction of enzyme-mimicking catalysts is a crucial route for achieving green chemical transformations;however,integrating multiple sites into one catalyst is challenging.Herein,a facile method is reported to combine different active sites by constructing a modularized catalytic system.A modularized catalytic system composed of covalent organic frameworks(COFs)and Cu_(2)Cr_(2)O_(5) exhibits remarkable efficiency in the transfer hydrogenation of cinnamaldehyde,with a selectivity of over 99%towards cinnamyl alcohol,surpassing the reaction rate of Cu_(2)Cr_(2)O_(5) by more than fourfold.The results of the mechanistic study and density functional theory calculations suggest that the enhanced activity of the modularized catalytic system is derived from the hydrogen bonds between the COFs and isopropyl alcohol,which promote isopropyl alcohol dehydrogenation and hydride transfer.In addition,the modularized catalytic system is efficient for various saturated and unsaturated aldehydes and could be replaced by different submodules.This study demonstrates the efficiency of a modularized catalytic system for mimicking the functions of enzymes in catalysis.

关 键 词：模块化催化体系 氢转移反应 氢键 类酶催化剂 共价有机框架材料 

分 类 号：O64[理学—物理化学]