Phosphine Catalyzed Asymmetric [1+4] Cycloaddition And Conjugate Addition

In recent years,the asymmetric synthesis catalyzed by nucleophilic phosphines has rapidly progressed as an efficient tool for preparing chiral organic molecules.Among the known chiral phosphine catalysts,chiral phosphine catalysts based on?-amino chiral phosphine skeletons are distinguished by their high efficiency and are a widely used class of catalysts.However,the common?-amino chiral phosphine has the defects of modification and modification difficult,single catalyst configuration.Therefore,the development of new skeleton?-amino-chiral phosphine catalyst is of great significance.In the first part of this article,we mainly explored the asymmetric[1+4]cycloaddition reaction of o-QMs with MBH carbonates.In order to achieve higher enantioselectivity results,we explored the catalysts in the basis of Wei-Phos.On the transformation,a novel chiral amide-diphosphine ligand catalyst was synthesized,and the catalyst was dehydrated and condensed with a commercially available aromatic aldehyde and an inexpensive chiral t-butyl sulfinamide to obtain chiral sulfinamide.By adding LiCH₂PPh₂ to it,Wei-Phos was obtained in high yield.Then the chiral inducing group tert-butylsulfinyl group was removed under acidic conditions to obtain?-amino chiral phosphine,and finally the amino group was further acylated to obtain novel chiral amide-phosphine bifunctional catalyst and successfully applied to the asymmetric[1+4]cycloaddition reaction.In the second part of this paper,to broaden the phosphine catalyzed reaction mode,we developed a Friedel-Crafts reaction of phosphine catalyzed p-QMs with naphthol to provide an efficient and convenient strategy for the construction of triarylmethane skeletons.The results showed that the co-catalysis of phosphine and methyl acrylate can effectively catalyze the aryl nucleophiles to achieve Friedel-Crafts reaction and obtain triarylmethanes.The chiral triaryl methane is an important class of structural units are widely found in natural products and drug molecules.Further,we proposed a reasonable reaction mechanism.In the third part,we successfully applied the co-catalysis of phosphine and methyl acrylate in Michael addition of TMSCN to trifluoromethyl ketene,and achieved excellent yield,which provided an efficient and convenient method for the organic-catalyzed cyanation reaction Strategy.This is the first case of a cyanation reaction catalyzed by organophosphine.This reaction has a broad range of substrate applications,mild reaction conditions,the resulting cyano product has potential applications in natural products and drug molecules.