Studies On The Hydrogen Bond-Mediated Asymmetric Cascade Reactions

Organocatalytic cascade reaction has various advantages over traditional stepwise synthesis such as high efficiency, operational simplicity and environmently friendliness and thus evolvs into the mostly exploited strategy for the generation of complex molecules from simple starting materials. As a continuing program to our group’s study in organocatalyzed efficient and green transformations toward functionalized molecules, this thesis mainly focus on the following three chapters:Chapter1:This chapter introduced the recent advances in the field of tetiary amine hydrogen-bongding bifunctional organocatalyzed asymmetric cascade reaction over the past decade.Chapter2:This chapter firstly described the recent advances of1,2-dicarbonyl compounds in asymmetric transformations. Then we presented a bifunctional squaramide promoted Michael/hemiacetalization of1,2-dicarbonyl and simple α,β-unsaturated enones for the synthesis of chiral functionalized3,4-dihydropyrones.Chapter3:This chapter presented the recent progress on organocatalyzed asymmetric synthesis of tetrahydrothiophenes and asymmetric synthesis of functionalized molecules containing a trifluoromethyl group. Next we described a bifunctional squaramide catalyzed sulfa-Michael/aldol between1,4-dithiane-2,5-diol (dimer of mercaptoacetaldehyde) and β-aryl-β-trifluoromethylated enones for the synthesis of the trisubstituted tetrahydrothiophenes with a trifluoromethylated quaternary stereocenter.