Carbon-Carbon Bond Activation By B(OMe)₃-mediated Fragmentation Borylation

Carbon-carbon bond cleavage has a wide range of applications in important industrial processes,e.g.in the petroleum chemistry,and in complex molecule synthesis.It enables the direct production of valuable functionalized products from widely available and inexpensive raw materials from nature resources and the chemical industry.In recent decades,the rapid development of methods for C–C bond activation has enabled cleavage of C–C bonds in strained systems via strain release,and of polar C–C bonds via oxidative addition(nitriles and ketones),b-carbon elimination(alcohols,amines and other substrates),oxidation,and other pathways.In contrast,non-polar unstrained C–C bond activation is still a major challenge and reported examples are rare.Current strategies for non-polar unstrained C–C bond activation mainly focus on transition-metal-catalysed reductive hydrogenolysis of substrates bearing two ortho directing groups.This thesis first discusses the different types of carbon-carbon bond activation reactions.Based on previous work,the activation of non-polar unstrained C–C bond is achieved by the fracture boronization reaction strategy promoted by B(OMe)₃.The main research results of the thesis are as follows:1.Using cheap and easily available B(OMe)₃ as a catalyst,the C2-selective carbon-carbon bond scission boronization reaction of 2-methylindole compound and B₂pin₂ was realized,and the range of substrates was expanded.2.With the equivalent of B(OMe)₃ as the accelerator,the selective carbon-carbon bond scission borylation reaction of 2-alkylindole compound or2-arylindole compound and B₂pin₂ at C2 was realized,and The range of substances has been expanded,and the mechanism of the reaction has been studied in detail.