Cobalt-Catalyzed Cyclization Addition Reaction Of 1,6-Enyne With Chalcone And Thiol

As an important building block of biologically important compounds,chemists have been involved in research on reactions of 1,6-enyne in recent years because of its high activity.1,6-enynes can undergo various types of reactions under relatively mild conditions.For example,cyclization reaction,addition reaction,etc.These reactions can react with some important pharmaceutical intermediates or relatively high activity compounds under milder conditions,thereby modifying or changing them on the basis of maintaining their characteristic pharmaceutical.1,6-Enyne can be cyclized into a five-membered ring or a six-membered ring under mild conditions,and these two cyclic compounds are precisely the more common structures in natural products and drug molecules.So,it is of great significance to investigate for development of inexpensive metals to catalyze the cyclization of 1,6-enynes to construct these "rings" through.Therefore,we tried to modify the chalcone,a common structure present in many natural products and molecules with biological activity,by the asymmetric addition reaction of 1,6-enyne.Fortunately,we used the cobalt catalytic system to obtain the asymmetric ring formation reaction of 1,6-enyne and chalcone with high stereoselectivity(93% ee)and moderately high yield(72%)addition products.The construction of carbon-heteroatom bonds has also been a very important reaction in organic synthesis,attracting the interest of many synthetic organic chemists and prompting them to develop new methods for these conversions.Among various carbon-heteroatom bond formations,carbon-sulfur(C-S)bond formation occupies an important position because organo sulfur compounds are widely present in nature and various biological systems.We used a cobalt catalytic system to control the addition reaction of 1,6-enyne with p-toluenethiol through different ligands.Unfortunately,due to the strong coordination ability of the sulfur atom,the enantioselectivity could not be controlled very well,but we obtained three different cyclization addition products in high yields and constructed different carbon-Sulfur bonds.