Oxindoles Formation Via Copper-Catalyzed Arylboration And Arylsilylation Of Alkenes

Oxindoles have a few bioactivities of antiinflammatory,antipsychotic,anticancer,antibacterial and widely existed in natural products,bioactive alkaloids,drug molecules and functional materials.It's vital importance that succeeding in synthesizing oxindoles quickly and efficiently by cheap metals catalysis.In this dissertation,by employing Cu OAc/1,10-Phen as a catalyst,a range of3,3?-Disubstituted oxindoles bearing an organoborane/organosilicon were obtained in a short time.With N-acryloyl-o-iodoaniline derivatives as the substrates,the major steps in this reaction are as follow:copper?I?transferred to Cu^I-Bpin intermediate by a transmetallation process.Then,insertion of activated alkenes and underwent intramolecular oxidative addition followed by reductive elimination to afford the corresponding borane-containing oxindoles.By systematically screening the catalysts,bases,ligands and catalyst amounts,the optimal conditions were defined as:cuprous acetate as catalyst,1,10-Phen as ligand,KO^tBu as base,B₂pin₂ as reagent,toluene as solvent and 100 ^oC.With the optimized reaction conditions in hand,the tandem cyclization reaction gave the desired boron-containing oxindoles bearing quaternary centers in moderate to excellent yields?25 examples,50-98%?and gave one boron-containing oxindole bearing tertiary center in 24%yield.With N-acryloyl-o-iodoaniline derivatives as the substrates,We use the same tandem cyclization strategy to afford the corresponding silicon-containing oxindoles.By systematically screening base amounts,temperature,the optimal conditions were defined as:cuprous acetate as catalyst,1,10-Phen as ligand,KO^tBu as base,Ph Me₂Si Bpin as reagent,toluene as solvent and room temperature.With the optimized reaction conditions in hand,the tandem cyclization reaction gave the desired silicon-containing oxindoles bearing quaternary centers in moderate to excellent yields?8 examples,52-90%?.