Catalyst-free visible-light-initiated oxidative coupling of aryldiazo sulfones with thiols leading to unsymmetrical sulfoxides in air

A facile and efficient visible-light-driven method has been developed to construct sulfoxides via oxidative coupling of aryldiazo sulfones with thiols using the O-2 in air as the oxidant. This reaction could be performed at room temperature under catalyst- and additive-free conditions. The present methodology offers a mild and environmentally benign approach to obtain a library of sulfoxides in good yields with favorable functional group tolerance.