Investigation On Allyl Compounds-participated Construction Of Carbon-carbon And Carbon-heteroatom Bond

In recent years,allyl compounds as a kind of highly active substrates with several reaction sites have been widely used in medicine,environmental,chemical,material,energy,and other fields.Since do not need to be functionalized in advance,allyl alcohol directly participated in coupling reaction which can effectively reduce the compound synthetic steps,improve the synthesis of atom economy,and reduce the by-products that bad for the environment.Meanwhile,allyl structure-oriented palladium-catalyzed cyclization reaction because of the diversity of allyl moiety raction sites and the flexibility of palladium-catalyzed initiating and quenching ways,could be used for high efficiency and high selectivity to construct new carbon-carbon and carbon-heteroatom bonds as well as the synthesis of complex reactive molecules.Due to the diversified reaction sites and the flexibility of initiating and quenching ways,how to achieve the chemical-and regio-selective reactions efficiently has the vital significance both in chemical fundamental research and the development of natural products and biologically active molecules.Therefore,we systematically studied the coupling reaction of the allyl alcohol as allyl precursor or aldehyde/ketone precursor,and designed a palladium-catalyzed fluoroalkylative cyclization of substrates with allyl structure to construct fluoroalkylated heterocyclic compounds,which would develope methods for building new carbon-carbon and carbon-heteroatom bonds with high efficiency,high atom economic,and high regioselectivity.The details are summarized as following:?1?Metal-free catalyzed regio-selective allylic trifluoromethanesulfonylation of aromatic allylic alcohols with sodium trifluoromethanesulfinate.An efficient procedure for the preparation of allylic trifluoromethanesulfones with high regio-selectivity from aromatic allylic alcohols/esters and NaSO₂CF₃ under transition-metal free conditions was described.We utilized the commercially readily,green,and low toxicity NaSO₂CF₃ reagent as triflyl source which would extend the potential application of allylic triflones in pharmaceutical and synthetic chemistry.A wide range of functional groups were tolerated.This was the first example to realize different types of allylic alcohols,including primary,secondary,and tertiary allylic alcohols,all of which transferred to the corresponding products efficiently in good to excellent yields.On the basis of the our results and previous reports,we proposed that the current reaction proceeds through a S_N1-type pathway by the formation of cationic?-allyl intermediates with strongly electrophilic properties.?2?Palladium-catalyzed desulfitative oxidative coupling between arenesulfinic acid salts and allylic alcohols:a strategy for the selective construction of?-aryl ketones and aldehydes.An efficient palladium-catalyzed desulfitative oxidative coupling of sodium arylsulfinites for highly regio-selective Heck-type reaction of allylic alcohols have been developed.This method provided a new and straightforward protocol for the synthesis of?-aryl ketones and aldehydes which widely exist in natural products and biologically active molecules using the commercially readily sodium sulfinites as aryl reagents.The compatibility of the functionalities of–I,–Br and–F would explore further post-functionalization of the C-X bonds.The deuterium labeling experiments indicated that this transformation may proceed via a 1,2-H shift process.?3?Palladium-catalyzed fluoroalkylative cyclization of allyl substrates.A palladium-catalyzed fluoroalkylative cyclization of allyl substrates with readily available R_f-I reagents to afford the corresponding fluoroalkylated 2,3-dihydrobenzofuran and indolin derivatives with moderate to excellent yields was reported.This novel procedure provided an efficient method for the construction of C_sp3-CF₂ and C-O/N bonds in a one-step.A wide range of functional groups were tolerated,such as halogens,acetyl,nitro,formyl,cyano,hydroxyl,etc.It was proposed that a radical/SET?single electron transfer?pathway proceeding via the fluoroalkyl radical may be involved in the catalytic cycle.