Studies On Constructing Carbon-carbon And Carbon-heteroatom Bonds By Pd-catalyzed C-H Bond Activation

Transition metal-catalyzed C-H bond functionalization has become one of the important means of modern organic synthesis due to its high efficiency,atomic economy and environmental friendliness.In the past few decades,palladium-catalyzed carbon-hydrogen bond activation reaction has been a hotspot in organic synthesis research,playing an important role in the synthesis of natural products,drug molecules and organic functional materials.The main research content of this paper is palladium-catalyzed carbon-hydrogen bond activation to construct carbon-carbon bonds and carbon-heteroatom bonds for the synthesis of small molecular compounds.The specific contents are as follows:1.Palladium-catalyzed hydrogenation arylation of non-terminal alkyneIn this part of the work,a versatile palladium-catalyzed hydroarylation of internal alkynes is developed.This reaction is under the coordination of Pd?PPh₃?₄,butyl formate and 1,5,7-triazabicyclo[4.4.0]dec-5-ene?TBD?,and the reaction conditions are mild.Diarylalkynes can offer hydrogenated arylation products in good yields.It also has good regioselectivity for asymmetric internal alkynes with electron-withdrawing groups.This system provides a new strategy for introducing olefin fragments on aromatic rings.2.Palladium-catalyzed acyloxylation of N-pyrimidinyl indoline/1,2,3,4-tetrahydroquinolineIn this part of our work,a palladium-catalyzed N-pyrimidine-directed acyloxylation reaction at the C-7/C-8 position of indoline/1,2,3,4-tetrahydroquinoline was developed.In the catalytic system of Pd?OAc?₂and iodobenzene acetate,this protocol provides highly selective acetoxylation products;at the same time,by changing the source of acyloxy groups,the corresponding acyloxylation products can also be obtained.The reaction operation is simple and provides an effective method for synthesizing indole or 1,2,3,4-tetrahydroquinolin derivatives.