A simple copper-catalyzed two-step one-pot synthesis of indolo[1,2-a]quinazoline

Abstract

SummaryA convenient CuI/L-proline-catalyzed, two-step one-pot method has been developed for the preparation of indolo[1,2-a]quinazoline derivatives using a sequential Ullmann-type C–C and C–N coupling. This protocol provides an operationally simple and rapid strategy for preparing indolo[1,2-a]quinazoline derivatives and displays good functional group tolerance. All the starting materials are commercial available or can be easily prepared.

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

“…In recent years, copper salts have been proven to be highly efficient catalysts in cross coupling reactions including Ullmann-type couplings reactions due to their low toxicity, high functional group tolerance and economical attractiveness. [10][11][12][13][14] Copper-catalyzed tandem reactions have emerged as powerful tools for the synthesis of polyheterocycles, [15][16][17][18][19][20][21][22][23][24] and some quinazoline fused heterocycles have been synthesized via copper-catalyzed tandem reactions. [25][26][27][28][29] Fu and co-workers synthesized benzo [4,5] imidazo [1,2-c] quinazolines was reported through copper-catalyzed crosscoupling reactions of 2-(2-halophenyl)-benzoimidazoles with aldehydes using sodium azide as the nitrogen source.…”

Efficient Pd-catalyzed domino synthesis of 1-phenyl-1H-indol-2-amine and 5-amino-indolo[1,2-a]quinazoline derivatives

“…11 A simple copper-catalyzed two-step one-pot synthesis of indolo[1,2-a] quinazolines in moderate yields was reported by Chunpu Li. 12 Cyano-substituted derivatives play an important role in organic synthesis. 13 As electrophiles, malononitriles were widely used for the formation of 1H-indol-2-amines, 2-amino-3-cyano-4H-pyrans and 1H-pyrazole-3,5-diamines.…”