Enantio- and Diastereoselective Synthesis of Highly Substituted Benzazepines by a Multicomponent Strategy Coupled with Organocatalytic and Enzymatic Procedures

Enantiomerically pure 4,5-dihydro-1<i>H</i>-benzo­[<i>c</i>]­azepines with three contiguous stereogenic centers have been assembled by convergent strategy with a good control of diastereoselectivity. The two steps are as follows: an asymmetric organocatalytic Mannich reaction performed on Boc-imines of <i>o</i>-(azidomethyl)­benzaldehydes, followed by a one-pot Staudinger/aza-Wittig/Ugi–Joullié sequence. The latter reaction represents one of the first examples of diastereoselective Ugi three-component reaction on a seven-membered cyclic imine. The <i>o</i>-azidomethylbenzaldehydes have been synthesized employing a simple and efficient chemoenzymatic strategy from commercially available building blocks