Metal-free visible-light induced cross-dehydrogenative coupling of tertiary amines with diazo compounds.

The first visible-light induced cross-dehydrogenative coupling between tertiary amines and diazo compounds is described. The reaction proceeds smoothly under mild and metal-free conditions by using air or O-2 as the oxidant, affording various beta-amino-alpha-diazo adducts in moderate to good yields with broad substrate scopes. The resulting products were successfully employed for the synthesis of 4- or 5-ester N-aryl-2,3-dihydrobenzo[d]azepines with high regioselectivity simply switched by the selection of the transition metal catalysts.