Photoredox-catalysed cyclisation of carbyne equivalents with alkenes and aldehydes to dihydrofurans

Herein, we report a multicomponent cyclisation reaction that employs a diazomethyl-substituted hypervalent iodine reagent as a carbyne source in combination with simple alkenes and aldehydes. This strategy successfully constructs dihydrofuran scaffolds, featuring broad substrate scope and excellent functional group compatibility. This work underscores the utility of carbyne as a versatile intermediate in organic synthesis.