Asymmetric synthesis of dibenzo[,]azepines by Cu-catalyzed reductive or borylative cyclization.

A copper-catalyzed asymmetric intramolecular reductive cyclization for the synthesis of dibenzo[,]azepines is described. Use of 2'-vinyl-biaryl-2-imines as substrates and formed [Cu/(Ph-BPE)] as the catalyst enables the synthesis of 7-membered bridged biarylamines containing both central and axial stereogenic elements in high yields (up to 98%) and with excellent diastereo- and enantioselectivities (>20 : 1 d.r., up to 99% ee). Moreover, the same catalyst was found to facilitate a related borylative cyclization to afford versatile boronic ester derivatives. Both reactions proceed under mild conditions (rt) and are applicable to a variety of substituted aromatic and heterocyclic derivatives.