Ni-Catalyzed Reductive Arylalkenylation of Alkynes for the Selective Synthesis of Polysubstituted Naphthalenes.

A Ni-catalyzed reductive arylalkenylation of alkynes with 1-bromo-2-(2-chlorovinyl)arenes in the presence of zinc powder has been developed. This base-free cyclization provides a novel protocol for the selective synthesis of 2-trifluoromethyl naphthalenes and ethyl 2-naphthoates from simple starting materials in moderate to good yields with excellent tolerance of functional groups.

Copper-Catalyzed Electrophilic Cyclization of N-Propargylamines with Sodium Sulfinate for the Synthesis of 3-Sulfonated Quinolines.

A convenient and effective protocol for the synthesis of 3-sulfonated quinolines via copper-catalyzed electrophilic cyclization of N-propargylamines has been developed, in which cheap and stable sodium sulfinates were utilized as green sulfonylation reagents. This cascade transformation involves radical addition, cyclization and dehydrogenative aromatization processes in a one-pot reaction under mild conditions.

Palladium-catalyzed dimerization of N-aryl propargylamines for the synthesis of 3-vinylquinolines.

A straightforward method for the synthesis of polyfunctionalized quinolines from readily available N-aryl propargylamines under aerobic conditions was developed. It provides convenient access to a variety of synthetically and pharmaceutically important quinolines in moderate to good yields. Control experiments suggest that the cascade reaction might proceed via the Pd-catalyzed electrophilic cyclization of N-aryl propargylamines followed by a hydroarylation process through trapping of the σ-quinolinylpalladium intermediate with a second molecule of the substrate.

One-Pot Synthesis of Quinoxalinones via Tandem Nitrosation/Cyclization of N-Aryl Cyanoacetamides.

A new one-pot strategy for the synthesis of quinoxalin-2-ones from the tandem nitrosation/cyclization reaction of N-aryl cyanoacetamides with tert-butyl nitrite has been developed. The dehydrogenative N-incorporation is achieved through a sequence of nitrosation, tautomerization, and cyclization, affording quinoxalin-2-ones in moderate to good yields with good functional group tolerance.

Copper-Catalyzed Three-Component Tandem Cyclization for One-Pot Synthesis of 1,4-Benzothiazines.

A copper-catalyzed three-component tandem reaction has been developed for the convenient and practical synthesis of 1,4-benzothiazines. A variety of terminal alkynes and 2-iodo/bromophenyl isothiocyanates underwent this one-pot cyclization with aqueous ammonia to afford 1,4-benzothiazines in moderate to good yields.

Synthesis of 2-Sulfenylindenones via One-Pot Tandem Meyer-Schuster Rearrangement and Radical Cyclization of Arylpropynols with Disulfides.

A tandem annulation of arylpropynols with disulfides has been developed for the synthesis of 2-sulfenylindenone derivatives. The reaction pathway involves one-pot tandem Meyer-Schuster rearrangement of arylpropynols and successive radical cyclization with disulfides. Various arylpropynols and disulfides with a number of functional groups are compatible in this reaction that affords the corresponding 2-sulfenylindenones in moderate to good yields.

Copper-mediated stereospecific C-H oxidative sulfenylation of terminal alkenes with disulfides.

A copper and iodine-mediated C-H oxidative sulfenylation of olefins with diaryl disulfides has been developed for the stereospecific synthesis of vinyl thioether. With the combination of Cu(OTf)2 and I2, a variety of terminal alkenes underwent oxidative coupling reaction with various diaryl disulfides successfully to afford the corresponding E-vinyl sulfides in moderate to good yields.

Copper-catalyzed ring expansion of 2-aminobenzothiazoles with alkynyl carboxylic acids to 1,4-benzothiazines.

A new ring expansion of 2-aminobenzothiazoles with alkynyl carboxylic acids was developed, which allows for one-pot synthesis of 1,4-benzothiazines in moderate to excellent yields. The cascade reaction was achieved through decarboxylative coupling, nucleophilic ring-opening reaction and intramolecular hydroamination process.

Oxidative tandem nitrosation/cyclization of N-aryl enamines with nitromethane toward 3-(trifluoromethyl)quinoxalines.

A novel one-pot strategy for the synthesis of 3-trifluoromethylquinoxalines from N-aryl enamines and nitromethane was developed. The tandem reaction is achieved through nitrosation of alkenes, tautomerization and cyclization, which can be applicable to a wide range of enamines with excellent functional group tolerance and afford quinoxalines in moderate to good yields.

FeCl3-promoted carboxamidation and cyclization of aryl isonitriles with formamides toward phenanthridine-6-carboxamides.

An iron-promoted tandem carboxamidation and cyclization between aryl isonitriles and formamides has been developed. The one-pot strategy can be applied to a wide range of 2-isocyanobiphenyls and formamides with excellent functional group tolerance for the synthesis of phenanthridine-6-carboxamides in moderate to excellent yields.