Study On C-C Bond Cleavage Reactions Of Carbonyl Compounds

C-C bond and C-H bond are two basic chemical bonds for the construction of organic compounds.The activation of C-H bonds has developed rapidly in recent decades,and has gradually become a common synthetic method.However,the activation of C-C bonds has just begun and is still in its infancy.In China,"Atomic economy and precise controllable synthesis methods and technologies"were identified as the priority areas for the development of synthetic chemistry during the13th Five-Year Plan period.This requires that synthetic chemistry must develop more efficient and sustainable methods.The reaction of C-C bond cleavage is the most direct method for organic synthesis,which meets the requirements of"atomic economy"and"step economy".This field has gradually become a research hotspot in recent years.The research on these reactions can not only provide new synthetic means for synthetic chemistry,but also support the sustainable development of human economy.Carbonyl group is the basic functional group in chemistry,thus it is universal to develop C-C bond cleavage reactions of carbonyl group.Carbonyl group has strong electron absorption effect,which makes the activation of C-C bond at alpha position of carbonyl group possible.In the classical organic transformation,only Baeyer-Villiger and Haloform reaction involve the C-C bond cleavage of carbonyl group.In this paper,we focused on the reactions of C-C bond cleavage.The first part:A metal-free PhI?OAc?₂-mediated method for the synthesis of acyl azides through oxidative cleavage of 1,3-diketones is described.This method is shown to have a broad substrate scope,providing a useful tool for multiproduct synthesis in single procedure.A possible reaction pathway is proposed based on mechanistic studies.The reaction conditions are mild and environmentally friendly.It meets the requirements of green chemistry and sustainable development.At the same time,it helps to understand the chemical nature of C-C bond cleavage and provides new ideas for the development of this field.The second part:Intramolecular CO extrusion–recombination reactions provide a powerful method for the formation of chemical bonds.In the past few decades,advances in decarbonylative bond formation,which can be used to create C–C,C–P,C–N,C–Cl and C–O,bonds through transition-metal catalysis,have been made.In this work,a method for Ni-catalyzed controlled decarbonylation of?-ketothioesters is described.Mono-and double-decarbonylations,which gave could decarbonylative coupling thioethers,respectively,were selectively achieved by changing the ligands.A fundamental study of Ni-catalyzed decarbonylation of?-ketothioesters is presented.The third part:we have demonstrated the efficient,high atom-economy,nickel-catalyzed intramolecular desulfonylative coupling of sulfonyl compounds.The reaction has good substrate applicability and functional group compatibility.This methodology not only provides a novel pathway for the catalytic conversion of sulfonyl groups,but is also expected to facilitate the discovery of important trends in nickel-catalyzed C-S bond activation.