| As a synthon with three carbon atoms,substituted cyclopropanes are widely used in the synthesis of various bioactive heterocyclic compounds.In recent years,donor-acceptor cyclopropanes were attracted a great deal of attention in organic synthesis research.D-A cyclopropane is termed as the abbreviated form of donor-acceptor substituted cyclopropanes.Not only was the term convenient for describing the vicinal relationship between the donor and acceptor substituents in cyclopropane ring,but also it pointed to the ability of cyclopropanes to react similarly to three-membered 1,3-dipoles,with their carbanionic center stabilized by an electron-withdrawing group(EWG)and their carbocationic centers stabilized by an electron-donating group(EDG).As special type of D-A cyclopropanes as three-carbon synthons,2-aroyl-3-aryl-l-cyanocycloprop-ane-l-carboxylates with one donor(aryl)and three acceptor(aroyl,cyano and carboxylate)substituents in the vicinal positions have been used in the construction of cyclic compounds.Because of the high polarization of two of three C-C bonds of the ring,the opening ring of 1-cyano-cyclopropane-1-carboxylates,2-aroyl-3-aryl-1,1-dicyanocyclopropanes promoted by various bases or acids yields 1,3-dipole intermediates to afford a variety of cycloaddition reactions.On the basis of our previous studies on the preparation and application of D-A cyclopropanes.In this paper,1-cyano-1-cyclopropane-1-carboxylates and 2-aroyl-3-aryl cyclopropane-1,1-dicarbonitrile as starting materials to synthesize pyrimidine derivatives,2-amino-4,6-diarylnicotino-nitrile derivatives and quinoline derivatives.The first part:A strategy to construct multi-substituted pyrimidine derivatives was developed by using 1-cyano-1-cyclopropane-1-carboxylates and amidine as starting materials.Under DBU mediated,pyrimidine derivatives were obtained in 58-85%yield.All products were characterized by NMR,IR and LC-MS spectroscopies.The second part:A new synthetic protocol of 2-amino-4,6-diarylnicotinonitrile derinatives was developed from 2-aroyl-3-nitroaryl cyclopropane-1,1-dicarbonitrile and thiourea.2-amino-4,6-diarylnicotinonitrile derivatives were finally obtained in 76-95%.Sixteen desired products were synthesized under the optimal reaction conditions.The third part:Different quinoline derivatives were synthesized by 2-aroyl-3-nitroaryl cyclopropane-1,1-dicarbonitrile and 2-aminobenzaldehyde via Yb(OTf)3-mediated.Under the optimal reaction conditions,quinoline derivatives were afforded in 59-82%yield.Thirty-two desired products were obtained.All products have been characterized by NMR,IR and LC-MS spectroscopies. |
