Visible-Light-Induced Radical C-N Coupling for Access to Hydrazine Derivatives.

We developed a facile visible-light-induced radical C-N coupling reaction to synthesize hydrazine derivatives. The reaction between azodicarboxylates and 2,3-dihydroquinazolin-4(1H)-ones can be carried out readily at room temperature and is free of any extra photosensitizers and additives. The yields of the target products ranged from 54% to 99%. This method is compatible with a wide range of substrates and functional groups. The practicality of the method is demonstrated through gram-scale synthesis and further product elaboration. Radical trapping experiments are consistent with a radical pathway. Taken together, this method provides a mild and environmentally friendly way to prepare hydrazines and valuable nitrogen-containing intermediates used in medicine.