One-Pot Three-Component Synthesis of Tetrahydro-1H-1,5-benzodiazepines

Significance

Reported is a simple and convenient one-pot three-component synthesis of ­tetrahydro-1H-1,5-benzodiazepine-2-carbox­amides from o-phenylenediamines, ketones and isocyanides. First performed is the in situ generation of diimines which undergo intramolecular cyclization to give dihydro-1H-1,5-benzodiazepines (not shown) which are subjected to reaction with isocyanides resulting in the formation of the target diazepines in good to excellent yields. The protocol uses simple and mild conditions allowing the synthesis of combinatorial libraries with various substitution patterns.