A palladium catalysed Ullmann biaryl synthesis has been developed using hydrazine hydrate as the reducing reagent at room temperature.

A metal-free protocol through visible light mediated oxidative cleavage of CC bonds to directly construct CN bonds has been developed for the conversion of alkenes to hydrazones under mild conditions.

A practical method has been developed for the conversion of alkenes to β-keto/hydroxyl sulfones by their reaction with sulfonyl hydrazides under metal-free conditions.

A green and cost-effective method has been developed for the conversion of alkenes to ketones under metal-free conditions.

Summary of main observation and conclusionAn operationally simple and safe synthesis of α‐haloketones using KBr and KCl as nonhazardous halogen sources is reported. It involves an iron‐catalysed reaction of alkenes with KBr/KCl using O2 as terminal oxidant under the irradiation of visible‐light. This strategy avoids the risks associated with handling halo‐contained electrophiles (Cl2, Br2, NCS, NBS). The process is tolerant to several functional groups, and extended to a range of substituted styrenes in up to 89% yield. A radical reaction pathway is proposed based on control experiments and spectroscopy studies.