tert-Amino Effect-Promoted Rearrangement of Aryl Isothiocyanate: A Versatile Approach to Benzimidazothiazepines and Benzimidazothioethers

A general and practical approach to benzimidazothiazepine and benzimidazothioether derivatives via an intramolecular nucleophilic addition/ring expansion rearrangement of aryl isothiocyanates promoted by the tert-amino effect has been developed. This reaction is catalyzed by low-cost camphorsulfonic acid and tolerates a broad substrate scope with complete atom economy. Structurally intriguing benzimidazothiazepine and benzimidazothioether products could be easily obtained by a simple operation in good to excellent yield (up to 98%).

A catalytic intramolecular nitrene insertion into a copper(i)–N-heterocyclic carbene bond yielding fused nitrogen heterocycles

We report a catalytic NHC–imido/nitrene cyclization allowing an easy access to diverse nitrogen-rich heterocyclic scaffolds.

One-pot synthesis of thiazino[2,3,4-hi]indole derivatives through a tandem oxidative coupling/heteroannulation process

A novel and expedient one-pot synthesis of thiazino[2,3,4-hi]indole derivatives was developed through a tandem oxidative coupling/heteroannulation process.

Copper-catalyzed tandem Ullmann type C-N coupling and dehydrative cyclization: synthesis of imidazo[1,2-c]quinazolines

A simple and efficient one-pot protocol has been demonstrated for the synthesis of imidazo[1,2-c]quinazoline derivatives through a copper catalyzed tandem reaction between substituted 2-(2-bromophenyl)-1H-imidazoles and formamide. The synthetic protocol involves initial Ullmann-type C-N coupling followed by intramolecular dehydrative cyclization. The method uses readily available 2-(2-bromophenyl)-1H-imidazoles as the starting materials to afford imidazo[1,2-c]quinazolines in moderate to good yields and provided 610 mg (71%) yield of 3a from a gram scale reaction.

Copper-catalyzed tandem N-arylation/condensation: synthesis of quinazolin-4(3H)-ones from 2-halobenzonitriles and amides

A novel, straightforward and practical copper-catalyzed domino protocol for synthesis of quinazolin-4(3H)-one derivatives from commercially available 2-halobenzonitriles and amides was successfully developed.