Visible light-induced synthesis of polysubstituted oxazoles from diazo compounds.

Herein, a visible light-induced synthesis of polysubstituted oxazoles from diazo compounds is reported. This developed synthetic method differs from traditional routes that rely on transition metals and external chemical oxidants. Our method uses readily available and inexpensive diazonium compounds as well as nitrile substrates with a catalytic amount of (i-Pr)SiCl species, delivering the corresponding valuable multi-substituted oxazole products (up to 95% yield). This protocol exhibits a broad substrate scope and is easily carried out under mild reaction conditions. Notably, gram-scale synthesis in a continuous flow fashion has been performed.