One-Pot Procedure for the Synthesis of 1,5-Benzodiazepines from N-Allyl-2-bromoanilines.

A new one-pot procedure that includes an initial titanium-catalyzed intermolecular hydroaminoalkylation of N-allyl-2-bromoanilines with N-methylanilines and a subsequent intramolecular Buchwald-Hartwig amination directly gives access to pharmacologically relevant 1,5-benzodiazepines. The process takes advantage of the excellent regioselectivity of the initial hydroaminoalkylation performed in the presence of a titanium mono(formamidinate) catalyst and the fact that the exclusively formed branched hydroaminoalkylation products can only undergo palladium-catalyzed cyclization to 1,5-benzodiazepines.