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 O2 as the oxidant, affording various β-amino-α-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.