基于Lewis酸活化惰性C-O单键氢解反应的研究

The transformation of C-O bonds via inert C-O bonds cleavage has become one of the most fascinating research topics in organic synthesis. Hydrogenolysis of inert C-O bonds seems to present a greater challenge compared to the formation of C-C bonds through transition-metal-catalyzed inert C-O bond cleavage. The propose is to develop a novel hydrogenolysis reaction system in which etheric C-O bonds are activated by boron reagents, based on our new strategy for the hydrogenolysis reaction catalyzed by transition metal complexes with Lewis acids as cocatalyst. By using intermediates trapping methods and modern testing techniques, such as X-Ray, NMR, MS and React-IR, in our propose, we will deeply study the activating procedure of the inert C-O bonds, the stablity of transition metal complexes of NHCs(N-heterocyclic carbene) with chelation groups and the selectivity of the inert C-O hydrogenolysis reaction, which will proved theoretical supports to keep on developing new hygrogenolysis reaction systems of inert C-O bonds. A new hydrogenolysis process of inert C-O bonds will be exploited and applied to the transformation of lignin from biomass into fuel and chemical feedstocks.

活化惰性C-O单键，实现C-O单键的官能团转化是有机合成化学的热点研究领域之一。相对于以惰性C-O单键构建C-C键，惰性C-O单键的氢解反应研究具有更大的挑战性。本项目基于Lewis酸硼试剂活化惰性C-O单键协助过渡金属催化C-O键的氢解反应这一策略，开发新型的醚类惰性C-O单键氢解反应催化体系，利用X-Ray、NMR、MS 及在线IR 等现代分析测试手段和中间体的捕获技术，深入探讨氢解反应中惰性C-O单键的活化历程，NHC（氮杂卡宾）配体中螯合基团对过渡金属-NHC络合物稳定性的影响，反应选择性控制等问题，为进一步开发惰性C-O单键氢解反应体系提供理论支持，凝炼出生物质木质素氢解生成燃料和化工原料的新技术。

实现惰性化学键的活化一直是化学工作者关注的焦点。本项目旨在发展活化惰性C-O键的反应体系，发展简单，高效的催化体系，探索有关反应的历程，得出了一些规律性的认识。具体内容如下：（1）发展过渡金属镍-NHC（氮杂卡宾）配体络合物催化剂体系活化惰性C-O键；(2)发展了一种活化惰性C-N键新方法；（3）通过各种手段，探索相关惰性化学键活化过程，并将这些高效的反应体系应用到复杂结构的具有潜在药物活性化合物的合成研究中。