Transition Metal Catalyzed Carbon-Carbon And Carbon-Hetero Cross Coupling Reactions

The transition metal catalyzed C-C and C-X bond cross coupling reactions have attracted much attention.The application of transition metal catalyzed organic molecules for the synthesis of many functionalization compounds are contribute to both the theory of organic chemistry development and the chemical industry application.In this thesis,the reported research of transition metal catalyzed C-S bond activation,?-C-H functionalization of carbonyl compounds and decarboxylative cross coupling reaction of ?,?-unsaturated acid is reviewed.Based on precious reports,we developed some new reactions.Results are summarized as follows: 1.Palladium catalyzed desulfuraive Sonogshira reactionA palladium catalyzed Sonogashira reaction of mercaptoN-heterocyclic derivatives with terminal alkynes by using CuI as thedesulfurative reagent was described in this report.A wide range of mercaptoN-heterocyclic derivatives and terminal alkynederivatives are compatible with the reaction.It provided aneffective strategy for obtaining Csp-Csp2 cross-coupling products ingood yields.The reaction mechanism was also investigated by densityfunctional theory?DFT?calculation.The rate determining step to thisreaction was the Pd?0?activated the C–S bond reaction.2.Copper catalyzed ?-C-H acyloxylation reactionA copper/TBHP catalyst system for the ?-C-H acyloxylation of carbonyl compounds has been developed by using terminal alkynes as the acyl carboxy.A variety of carbonyl compounds and terminal alkynes were tolerated in this reaction.In addition,a radical-based mechanism was also proposed.3.KI/K₂S₂O₈ mediated ?-C-H thiolation reactionThe KI/K₂S₂O₈ mediated ?-C-H thiolation cross coupling of carbonyl compounds with thiols towards the synthesis of ?-keto sulfones was investigated at room temperature under metal-free conditions.Good yields and selectivities were obtained for a range of substrates.A wide range of aromatic ketone or hetero ketones substrates are compatible with the reaction.On the basis of mechanistic studies,a possible reaction mechanism is proposed.4.Iron catalyzed decarboxylative nitration reactionA noval and efficient method for the synthesis of E-nitroolefins in moderate to excellent yields is developed by Fe???/pyridine-meidate decarboxylative nitration of ?,?-unsaturated acids with iron nitrate.A series of ?,?-unsaturated acids are well tolerated in this procedure.A free radical mechanism is also proposed by DFT study.