Atom Transfer Radical Thiosulfonylation Of Unsaturated Carbon-Carbon Bonds With Dual Gold And Photo Catalysis

Recently,scientists tried to combine the transition-metal catalysis and photo catalysis together to overcome the challenges in organic synthesis through cocatalysis strategy.In this thesis,the recent developments on novel organic reactions realized by dual late transient metal catalysis(Ni,Pd,Cu,Au)and photo catalysis strategy were reviewed.On the basis of these research,we developed thiosulfonylation reaction of unsaturated carbon-carbon bonds through dual gold and photo catalysis strategyIn chapter I,intermolecular atom transfer thiosulfonylation of alkenes was described.Aryl diazonium salts are the only formal oxidant can be used in previous dual gold/photo catalysis system,and herein we developed a novel formal oxidant PhSO2SR instead of aryl diazonium salts.Highly regioselective and stereoselective thiosulfonylation of alkenes can be realized under mild conditions and without external additives.Detailed mechanism studies indicate that the gold catalyst experiences four different valencies from Au(0)to Au(?),which is unprecedented in previously reported Au-catalyzed transformations.In chapter ?,intermolecular atom transfer thiosulfonylation of alkynes was described.We have developed a gold/photo cocatalyzed thiosulfonylation reaction of alkynes in the most atom economical manner with very low catalyst loading and no need of external additives.The improvement of reaction yield and stereoselectivity in the presence of gold catalyst indicated the importance of gold catalyst.The novel alkenes with SCF3 and SCF2H groups were first synthesized through transformations of products.Detailed mechanism studies indicated a possible radical chain reaction process.In chapter III,intermolecular atom transfer thiosulfonylation of enynes was described.Thiosulfonylation reaction of enyne through dual gold/photo catalysis can be realized under mild condition and two different regioselectivity can be controlled to realize the construction of five member or six member carbo-and heterocycles.