银催化炔烃活化模式的理论研究

The activation of the carbon-carbon triple bond in alkyne for subsequent transformation reactions is a key step in organic reactions. Silver-catalyzed alkyne activation-functionalization is a powerful strategy for the construction of various organic molecular skeletons, which has received considerable attentions over the past several decades. According to the literature research and our preliminary theoretical studies, transition metal catalyzed alkyne activation could be realized through many possible pathways, for example, (a) π-electrophilic activation, (b) σ-nucleophilic activation, (c) σ,π-electrophilic activation, (d) redox activation, and (e) σ-electrophilic activation. In this project, the mechanisms of three types of selected reactions are studied theoretically, which included silver-catalyzed [5+2] cycloaddition of γ-amino ketones with alkynes, silver-amine co-catalyzed Conia-ene reaction, and silver-catalyzed cyclization of 2-pyridyl alkynyl carbinols with isocyanides. Our theoretical studies will mainly focus on the activation of alkynes. We would build the silver-catalyzed alkyne activation models, and elucidate the detailed mechanism of this elementary reaction. On this basis, we expect to explore the impact of the substrates and co-catalysts on the alkyne activation models, reactivity, and chemical selectivity. Moreover, we will summarize the general rule that the substrates and co-catalysts affect the reaction mechanism, which will benefit the corresponding experimental works. It is believed that the research results of this project will provide valuable basis and theoretical information for understanding the mechanism of transition metal catalyzed alkyne activation-functionalization in molecular level.

C-C叁键的活化是炔烃参与有机反应的关键步骤，银催化剂可以有效的催化炔烃活化，被广泛地应用于构建各种复杂的有机分子骨架，极大地推动了炔化学的发展。过渡金属催化炔烃活化的可能方式主要有π-亲电活化、σ-亲核活化、σ,π-亲电活化、氧化还原活化和σ-亲电活化等。本项目中，申请人将针对实验报道的有可能经历这几种炔烃活化模式的银催化制备吖庚因衍生物、亚甲基环戊烷、氮杂茚和吡咯类衍生物等反应进行机理研究，将关注的焦点集中在炔烃活化上。希望通过此研究，建立银催化炔烃活化的模型，明确银催化炔烃活化的详细机制。在此基础上，揭示不同类型炔烃底物、共催化剂等对银催化炔烃活化模式、反应活性和选择性的影响，凝练影响反应机理的内在规律，建立反应机理模型，为相关实验工作提供有价值的信息和理论指导。本项目的开展可深化对过渡金属催化炔烃活化机制的理解，具有重要意义。

过渡金属催化炔烃活化-官能团化反应可用于构建各种复杂的有机分子骨架，极大地推动了有机化学的发展。本项目利用密度泛函理论方法研究了银、铑、钌等过渡金属催化炔烃活化-官能团化反应的机理，确定了反应中间体及过渡态的结构，提供了反应过程中定量的热力学及动力学数据，阐明了底物、取代基、共催化剂等各种反应条件对炔烃活化模式及反应活性和选择性的影响，研究成果将有助于构筑完整的过渡金属催化炔烃活化模型，深化对过渡金属催化炔烃活化-官能团化反应机制的理解，为炔烃活化反应的进一步研究和设计提供有价值的信息和理论依据。本项目还对Ag/Cu共催化芳基取代的异恶唑C-H烯基化反应进行了理论研究，阐明了催化剂和导向基团影响产物区域选择性的成因，为理解和设计新型的双金属催化的相关反应提供了理论参考；对钯催化芳基卤化物二硅烷基化反应进行了理论研究，确定了最有利的反应路径，利用NPA电荷分析探讨了C-I/Si-Si键与Pd(0)/Pd(II)之间氧化加成的异同，加深了对二硅烷基化反应的理解；对铑催化芳香酸C-H烯烃化反应进行了理论研究，阐明了反应的详细机理，探讨了位阻效应和电子效应等对反应区域选择性的影响，为相关实验工作提供有价值的信息和理论指导。此外，本项目还对其它过渡金属催化的有机反应进行了理论研究，取得一系列的成果，促进了金属有机化学的发展。