Design And Synthesis Of Novel Chiral Guanidinium Salts Phase Transfer Catalysts And Green Synthesis Of Gem-diarylmethyl Sulfones

The project is aim to design and synthesize a novel chiral guanidinium salt phase transfer catalyst based on binaphthyl group.These classes of chiral guanidinium salt phase transfer catalysts which are sp~2-quaternized ammonium salts have some advantages,such as high degree of dispersion of the charge,high chemical and thermal stability,convenience to modify the R group in both nitrogen and binaphthyl groups,easy to get raw materials and so on.The resulting catalyst was used for asymmetric alkylation of dibenzylidene glycine tert-butyl ester with halocarbons and asymmetric Michael conjugate addition reaction of dibenzylidene glycine tert-butyl ester with chalcone.The experimental results show that these two types of catalysts exhibit some catalytic activity in asymmetric alkylation and asymmetric Michael conjugate addition reaction.Asymmetric Michael conjugate additions gave 74-90%yields with>20/1 diastereoselectivity and 3-18%enantioselectivity.80-90%yields and 5-20%enantioselectivities are obtained in asymmetrical alkylation reactions.The regularity presented in the experiment indicates the direction for future work on chiral yttrium salt phase transfer catalysts.At the same time,it provides a convenient and quick route for the synthesis of novel chiral sulfonium compounds.In this paper,A class of gem-diarylmethyl sulfones were synthesized via the1,6-conjugate addition reaction of arylsulfonyl hydrazide and para-Quinone methides in aqueous phase.26 Compounds were obtained with yields ranging from 52%to96%.Metal catalyst and anhydrous oxygen-free operation were not needed.At the same time,we carried out a gram-scale expansion of the reaction with 73%yield.We also confirmed that this reaction has a large number of synthetic industrial applications.Besides,we derivatized the product and achieved the conversion of the gem-diarylmethyl sulfones to the diarylmethyl thioether compounds and the diarylmethyl substituted amino acid compounds.