Diarylprolinol Silyl Ether Catalyzed Cascade Reaction To Construct Highly Functionalized Five-membered Lactones

In recent years,Organic-catalyzed cascade reactions have become a powerful strategy for constructing highly functionalized chiral γ-lactones.These reactions can quickly build complex structures with high enantioselectivity,but the yield and diastereoselectivity are generally unsatisfactory due to the large number of substrate reaction sites.In this paper,the cascade-cyclization catalyzed by diarylprolinol silyl ether were studied,and a class of highly functionalized chiral γ-lactones were successfully synthesized.In this paper,the diarylprolinol silyl ether catalyzed conjugative addition-cyclization of γ,γ-disubstituted α,β-unsaturated aldehydes with 3-benzoylacrylic acid was accomplished,providing highly functionalized chiral γ-lactones.Screening catalyst types,solvents,and reaction temperatures,the highly functionalized chiral γ-lactones could be constructed with high diastereoselectivity and enantioselective in moderate yield.Meanwhile,a feasible mechanism was proposed for the reaction process through verification experiments.Finally,a variety of chiral γ-lactone structure were prepared by transforming the products of the reaction.Additionally,the cascade cyclization catalyzed by diarylprolinol silyl ether overcomes the disadvantages of low yield and low diastereoselectivity.At the same time,this reaction could be accomplished under mild conditions with high efficiency.The unsaturated aldehydes and acid with various functional group shown good tolerance.Moreover,the convertible functional groups in the products provide a new strategy for the synthesis of highly functionalized chiral γ-lactones.