Pd-catalyzed Desulfitative Heck-type Coupling And Conjugate Addition

In the past few decades,selectively catalyzed reaction is becoming the most important methods in contemporary chemistry of formation C-C and C-heteroatom bond.A mount of transition metal catalyzed reaction system was developed,such as Suzuki,Negishi,Still,Kumada reaction.However,these reactions are insufficient for equivalent of metal were needed while convert original substrates into highly reactive organometallic compounds,and these steps are necessary.In recent years,chemists are interested in replacing organometallic substrates with organic functions groups as leaving group for C-C and C-heteroatom bond formation.Our research aimed on a new aryl source for Heck reaction and conjugate addition powered by palladium-catalyzed desulfitative of arenesulfinic aicd sodium salts.Herein,we report a palladium-catalyzed desulfitative Heck coupling of arenesulfinic acid sodium salts with alkenes at 85 ? using oxygen as the terminal oxidant.After experimental analysis of the catalyst,ligand,solvent and temperature of desulfitative Heck coupling reaction,the optimum condition were founded.Different substituents of substrates effects on the reaction were investigate under the best conditions.A plausible mechanism to rationalize this transformation is founded.A palladium-catalyzed desulfitative conjugate addition of arenesulfinic acid sodium salts with ?,?-unsaturated compounds were performed.We found that arenesulfinic acid sodium salts can addition to ?,?-unsaturated compounds for the nucleophilicity after desulfitative.The conjugate addition reaction has highly selectivity and no by-product was observed.Mechanism of reaction is not clear for the moment.A chiral carbon atom was emerged in the addition product in this reaction,and the temperature is moderate.This research established a foundation for future asymmetric conjugate addition reaction.