Visible-light-induced decarboxylative cascade cyclization of acryloylbenzamides with N -hydroxyphthalimide esters via EDA complexes.

A visible-light-induced decarboxylative cascade reaction of acryloylbenzamides with alkyl N -hydroxyphthalimide (NHP) esters for the synthesis of various 4-alkyl isoquinolinediones mediated by triphenylphosphine (PPh 3 ) and sodium iodide (NaI) was developed. This operationally simple protocol proceeded via the photoactivation of electron donor-acceptor (EDA) complexes between N -hydroxyphthalimide esters and NaI/PPh 3 , resulting in multiple carbon-carbon bond formations without the use of precious metal complexes or synthetically elaborate organic dyes, which provided an alternative practical approach to synthesize diverse isoquinoline-1,3(2 H ,4 H )-dione derivatives.