Zn-mediated catalytic photoreduction of aldimines. One-pot synthesis and separation of meso and d,l C2 symmetrical diamines

A new one-pot method for the synthesis and selective separation of 1,2-diamines is reported. The methodology, which involves the photoreduction of imines using catalytic amounts of zinc as a photosensitizer, allows the direct preparation and separation of meso and d,l compounds on a multigram scale.