Phosphine-catalyzed Or Metal-catalyzed Cycloadditions Of Zwitterionic Intermediates With 1,3-Dipoles

Nitrogen-containing heterocyclic compounds play an important role in the pesticides,medicine,material and other fields of fine chemical industry.Due to the importance of these compounds,it is vitally necessary to develop green,economic and efficient methods.1,3-Dipolar cycloaddition reactions represent an important class of synthetic methods for the convergent synthesis of a wide range of heterocycles,and have attracted much attention.In this paper,phosphine-catalyzed or metal-catalyzed annulation reactions of stable 1,3-dipoles with reactive dipolar species are described,affording a series of five-to eight-membered nitrogen-containing heterocyclic compounds which possess potential biological activities.We aim to discover new pesticides with biological activity from these compounds.A novel phosphine-catalyzed[3+2]annulation reaction has been presented.Phthalazinium dicyanomethanides reacted with allenoates to give a series of tetrahydropyrrolophthalazine derivatives in 91-99%yields,dihydropyrroloisoquinoline product in 88%yield and dihydropyrrolopyridazine product in 79%yield under mild conditions,and the reaction underwent very well to give the cycloadduct in 98%yield on the gram scale.This novel phosphine-catalyzed[3+2]cycloaddition provides a new methodology for synthesis of nitrogen-containing heterocyclic compounds.The first example of chiral phosphine-catalyzed enantioselective[4+3]annulation reaction has been developed,affording chiral tetrahydrodiazepinoquinazoline derivatives with in high yields(up to 98%)with excellent diastereoselectivities(up to 33:1)and enantioselectivities(up to 96%)under mild conditions.With the use of an oxidation-ring-opening procedure,chiral monocyclic diazepine derivatives were produced without loss of dr and ee.The enantioselective[3+3]annulation of phthalazinium dicyanomethanide and iminoester-derived azomethine ylide catalyzed by Cu(1)has been developed,giving a series of chiral piperazine derivatives in high yields with excellent stereoselectivities(up to 99%yield,up to>20:1 dr and up to 99%ee).The reaction worked very well to give the cycloadduct on the gram scale(95%yield,>20:1 dr and 94%ee).A palladium-catalyzed[5+3]cycloaddition of N-iminoquinazolinium ylides with vinylethylene carbonates as five-membered synthons for the synthesis of eight-membered N,O-containing heterocycles has been developed,providing medium-ring heterocycles in high yields with excellent chemoselectivities.