Carbon-hydrogen Bond Activation And Diversification Of Biomass-based Oxygen-containing Small Molecules

Catalytic transformation of renewable resources is an important issue of chemistry that orients towards sustainable development,in which a frontier is synthesis of value-added products from biomass-derived building blocks.Though extensive studies have been performed via functional group conversion,condensation and hydrogenation of biomassderived oxygen-containing molecules,the reaction types and product diversity are still limited.In this thesis,with reaction design based on the structural characters of several types of bio-based molecules,and facilitated by transition metal catalyzed and carboxyl directed C–H activation,the cross coupling reaction of furan derivatives and carboxyl acids and coupling–cyclization one-pot reaction were investigated and developed,which provides new strategies for utilization of renewable resources and post-functionalization of drugs.The main content of this thesis contains three parts.In the first part,the research background was summarized,and progress on C–H coupling,carboxyl directed C–H functionalization and upgrading of bio-based molecules were reviewed.On this basis,general research outline of the thesis was proposed.The second part is research on cross coupling of furan derivatives and carboxyl acids via Ir-catalyzed C–H activation.With systematic screening and optimization of conditions,a green,efficient and convenient Ir/Cu catalysis and air oxidation system was established,and a series of functionalized coupling products were synthesized using furan derivatives and diverse carboxyl acids.Among them,integrative utilization of two different types of biomassderived building blocks was realized by using vanillic acid ant its derivatives as the carboxyl acid substrates.Furthermore,cross coupling of several carboxyl-containing drugs and furan derivatives was explored,opening a new avenue for post-functionalization of drugs and upgrading of biomass-derived molecules.The third part is research on multiple C–H activation and diverse one-pot reactions of biomass-derived oxygen-containing molecules.After previous Ir-catalyzed coupling reaction,Ru catalyst and the third component alkene were added in situ,which enabled the carboxyl group to direct C–H activation on the other ortho-site to realize one-pot alkene cyclization.On this basis,the application of this one-pot reaction strategy for post-functionalization of drugs was explored,while one-pot conversion of three different types of renewable molecules was realized using dimethyl itaconate as the alkene.Furthermore,a coupling–alkenation one-pot reaction was discovered,and the one-pot strategy was extended to coupling–alkyne cyclization.