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Theoretical Study on Bonding and Catalytic Properties of N-heterocyclic Carbenes and Aluminum Carbenoids

Abstract

氮杂环卡宾(N-heterocycliccarbene,NHC)中sp2杂化的卡宾碳具有独特的σ2π0电子结构,表现出较强的σ给电子能力和一定的π电子接受能力。作为σ型的配体,NHC可以与过渡金属(Transitionmetal,TM)原子相互作用形成σ-型配合物,并导致过渡金属中心呈现出富电子特征,使其在催化反应中具有较高的反应活性。强亲核性的NHC进攻醛,可以使其由亲电试剂反转为亲核试剂,所产生的Breslow中间体具有较高的反应活性,能与多种亲电试剂发生丰富的化学反应。当醛上具有不饱和共轭链时,反应的活性位点可以传递到远端δ位的碳原子上,并发生和1,6−Michael加成反应...In the N-heterocyclic carbene (NHC), the carbene carbon adopts the sp2 hybridization with a special σ2π0 electronic structure, and shows the ability of stronger σ-electron donor and weak π-electron acceptor. The σ dative bond between NHC and the transition metal (TM) results in a rich electron TM center with high catalytic reactivity. As a nucleophilic catalyst, NHC combines with an electrophilic ...学位:理学博士院系专业:化学化工学院_物理化学学号:2052013015388

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