Daqing Shi

Synthesis of quinazolin-4(3H)-ones and 1,2-dihydroquinazolin-4(3H)-ones with the aid of a low-valent titanium reagent

Abstract A short and facile synthesis of a series of quinazolin-4(3H)-ones and 1,2-dihydroquinazolin-4(3H)-ones was accomplished in good yields via the novel reductive cyclization of o-nitrobenzamides and triethyl orthoformate, aldehydes or ketones promoted by TiCl4/Zn.

A Convenient Synthesis of 5-Oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran Derivatives Catalyzed by KF-Alumina

Abstract A series of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives were prepared by the reaction of arylmethylidenemalononitriles or 2-cyano-3-aryl-l-acrylate with 5,5-dimethyl-1,3-cyclohexanedione (dimedone) in DMF at room temperature catalyzed by KF-alumina. The structure of the product was confirmed by X-ray analysis.

Low-valent titanium induced reductive coupling reaction of carboxylic derivatives with aromatic ketones

Abstract The intermolecular and intramolecular coupling reaction of carboxylic derivaties with aromatic ketones induced by titanium tetrachloride and zinc powder was studied.

A CONVENIENT SYNTHESIS OF 2,4-DIARYLPOLYHYDROQUINOLINE DERIVATIONS IN THE PRESENCE OF AMMONIUM ACETATE

ABSTRACT A series of substituted 5-oxo-1,2,3,4,5,6,7,8-octahydroquinoline derivatives have been synthesized from 5,5-dimethyl-1,3-cyclohexane-dione (dimedone) and 1,3-diaryl-2-propen-1-one in DMF at 80°C in the presence of ammonium acetate with high yields (64–98%), the structure of the product was confirmed by X-ray analysis.

Three-component processes for the synthesis of 4-aryl-7,7-dimethyl- 5-oxo-3,4,5,6,7,8-hexahydrocoumarin in aqueous media

The reaction of an aromatic aldehyde, isopropylidene malonate and 5,5-dimethyl-1,3-cyclohexanedione in water in the presence of triethylbenzylammonium chloride (TEBA) as catalyst affords a one-pot synthesis of 4-aryl-7,7-dimethyl-5-oxo-3,4,5,6,7,8-hexahydrocoumarin.

A CONVENIENT SYNTHESIS OF 2-AMINO-1,3,3-TRICYANO-5-NITRO-4,6-DIARYLCYCLOHEXENES CATALYZED BY KF-ALUMINA

ABSTRACT A series of 2-amino-1,3,3-tricyano-5-nitro-4,6-diarylcyclohexenes were synthesized by reaction of aryl-methylidenemalononitriles and nitromethane catalyzed by KF-alumina. Its structure was determined by single crystal X-ray diffraction.

Facile Synthesis of Substituted Quinazolin‐4‐(3H)‐ones Using Low‐Valence Titanium Reagent

Abstract A short and facile synthesis of a series of 3‐aryl quinazolin‐4‐(3H)‐ones was accomplished in good yields via the intermolecular reductive coupling reaction of N‐aryl‐2‐nitrobenzamide and triethyl orthoformate promoted by TiCl4/Zn.

A novel reductive cyclisation of o-nitrochalcones promoted by low-valent titanium: an access to 2-arylquinolines and 5,6-dihydrobenz[c]acridines

The intramolecular reductive cyclizations of o-nitrochalcones(1) induced by the TiCl4/Zn system were studied; 2-arylquinolines(2) and 5,6-dihydrobenz[c]acridines(4) were obtained in reasonable yields at room temperature conditions.

Synthesis and crystal structure of 7,7-dimethyl-2,4-diphenyl-5-oxo-1,4,5,6,7,8-hexahydroquinolin

AbstractThe 7,7-dimethyl-2,4-diphenyl-5-oxo-1,4,5,6,7,8-hexahydroquinolin was synthesized and the compound was identified by IR, 1H NMR, elemental analysis and X-ray crystallography. It crystallized in the triclinic space group