An asymmetric three-component reaction of a diazo compound with an alcohol and a seven-membered imine

A dirhodium and chiral phosphoric acid co-catalyzed asymmetric three-component reaction of a diazo compound with an alcohol and a seven-membered imine has been developed via Mannich-type interception of a transient oxonium ylide. This reaction provides an efficient approach for the synthesis of chiral dibenzoazepine analogues, including dibenzo[b,f][1,4]oxazepine, dibenzo[b,f][1,4]thiazepine, and dibenzo[b,e]azepine derivatives, in generally good yields with excellent stereoselectivity (91%–99% ee) under mild reaction conditions. This reaction shows broad substrate generality, and these generated products could be further converted to enantioenriched tetracyclic frameworks with embedded functional groups.