Study On Cycloaddition Reaction Of Azaaromatic Quaternary Ammonium Salts And 2-arylidene-1,3-Indanediones

Heteroaromatic N-ylides,usually generated in situ from the corresponding salt through base promotion,have been attracting continuous attention due to their versatile reactivity.The most common reaction of Heteroaromatic N-ylides is the[3 + 2]cycloaddition reaction with various 1,3-dipolarophiles to construct nitrogen-containing heterocyclic systems.2-Arylidene-1,3-indanediones as one of 1,3-dipolarophiles could be used in cycloaddition reaction.In this paper,we carried out some addition reactions of azaaromatic quaternary ammonium salts and 2-arylidene-1,3-indanediones to synthesis a series polycyclic compounds.1.A mixture of isatin,inden-1,3-dione and N-phenacylpyridinium bromides in ethanol was refluxed in the presence of triethylamine and a novel ring-expanded 5H-benzo[b]naphtha-[2,3-d]azepine was obtained.Although the carboxyl and carboxamide group are less electron-withdrawing than the phenacyl group,the two-carbon ring expansion was still carried out under the same reaction conditions.But in the presence of a less electron-withdrawing p-nitrobenzyl group at the N-substituent of pyridinium salts,the reaction stops at the zwitterionic stage.All products were characterized by IR,1H NMR,13C NMR,HRMS spectroscopy.The single crystal structures of four products were determined by X-ray diffraction method.2.A unique[3+2]-[4+2]-[3+2]cycloaddition sequence of isoquinolinium ylide with aromatic aldehydes and indan-1,3-dione is investigated to afford polycyclic compounds with ten stereogenic centers in moderate to high yields.The observance of only one diastereomer verified the very high regio-and diastereo-selectivity.In this three-component reaction,the isoquinolinium salt has a triple function as a 1,3-dipole,an electron-rich dienophile and an electron-deficient diene.All products were characterized by IR,1H NMR,13C NMR,HRMS spectroscopy.The single crystal structures of three products were determined by X-ray diffraction method.3.The base-promoted cycloaddition reaction of N-cyanomethylisoquinolinium chloride with 2-arylidene-1,3-indanediones in dry tetrahydrofuran resulted in the expected spiro[indene-2,1’-pyrrolo[2,1-a]isoquinoline]derivatives.However,the triethylamine-promoted three-component reaction of N-cyanomethylisoquinolinium chloride,aromatic aldehydes,and afforded unique spiro[benzo[f]imidazo[5,1,2-cd]-indolizine-4,2’-indene]derivatives in satisfactory yields through tandem double[3+2]cycloaddition reactions.During our investigation on this topic,sometimes,we found that a unique polycyclic compound might be separated in very lower yield from the reaction mixtures.It was constructed by one benzaldehyde and four molecules of 1,3-indandione.All products were characterized by IR,1H NMR,13C NMR,HRMS spectroscopy.The single crystal structures of five products were determined by X-ray diffraction method.