Chiral Organomolecular And Bis(oxazolines)-Metal Complex Catalyzed Asymmetric Tandem Reaction Of Enones

In the area of modern synthetic chemistry,both organocatalysis and metal catalysis have played important roles in the field of asymmetric synthesis.Complex chiral organic molecular attract intensive attention of organic chemists,which could be directly synthesized by the use of ordinary and inexpensive substrates under organocatalysis and metal catalysis.In this thesis,enone derivatives serve as important and versatile synthons and employed into carbon-carbon and carbon-hetero atom formation reactions in an asymmetric tandem manner.In the first part,a series of chiral diamine derivatives has been synthesised by the use of optically pure 1,2-diphenylethylenediamine(DPEN)as starting materials.In the second part,highly efficient[3+3]tandem Michael-cyclization reaction between isatin-derived ?,?-unsaturated a-ketoesters and 3-hydroxy-4H-chromen-4-ones,which catalyzed by quinine-derived bifunctional tertiary amine-thiourea catalysts.After optimization of reaction conditions,a series of spiro[oxindole-pyrano[3,2-b]chromenone]derivatives,bearing a spiro quaternary and hemiketal stereogenic center,was obtained in high yields with enantiomerically enriched.In the third part,an asymmetric organocatalytic domino cyclization reaction of dienones and azlactones has been achieved in the presence of a bifunctional cinchona alkaloid squaramide organocatalyst.This reaction affords good to excellent yields of indane derivatives bearing chiral quaternary stereo center scaffolds and four adjacent stereogenic centers.In the fourth part,an asymmetric[4+2]cyclization reaction of ortho-hydroxyphenyl-substituted para-quinone methides and azlactones has been successfully developed by the use of a Bis(oxazolines)-Cu(II)complex.This domino reaction affords an efficient and mild synthetic method and accesses to chiral dihydrocoumarins bearing a quaternary amino acid moiety and quaternary stereogenic centers with excellent diastereo-and enantioselectivities.In the fifth part,an asymmetric[3+2]desymmetrization cyclization reaction of donor-acceptor cyclopropanes and cyclopentenediones has been successfully developed by the use of a Bis(oxazolines)-Fe(III)complex.This cyclization reaction affords an efficient and mild synthetic method and accesses to chiral scaffolds bearing an adjacent tertiary and quaternary stereogenic centers with mild enantioselectivities.