A transition-metal free thio/selenocyanation of oalkenyl benzoic acids via the electrophilic ClÀ S(Se)CN species, in-situ generated from inorganic thio/selenocyanating salt and PhICl 2 , has been realized under mild reaction conditions. This protocol offers a divergent synthesis of thio/selenocyanated isobenzofuranones and isocoumarins, depending on the substitution type of the substrates.

The treatment of 2-alkenylanilines with phenyliodine(III) diacetate (PIDA) and LiBr or KI in HFIP was found to afford the corresponding 3-haloindoles via cascade oxidative cyclization/halogenation encompassing oxidative C–N/C–X (X = Br, I) bond formations. A plausible mechanism involving the in situ formation of the reactive AcO-X (X = Br, I) from the reaction of PIDA and LiBr/KI was postulated.

In the past few decades, the chemistry of hypervalent iodine reagents has undergone a flourishing development in synthetic organic chemistry owing to their mild oxidative, low toxicity, air and moisture stability and environmentally benign features. A plethora of oxidative coupling reactions have been conducted using hypervalent iodine reagents as a nonmetallic oxidant. In particular, the C-S and C-Se bond forming reactions mediated by hypervalent iodine reagents have emerged as a powerful approach in the construction of S-containing and Se-containing heterocycles or building blocks. In these reactions, hypervalent iodine reagents behave as strong oxidants or electrophiles and activate the S-containing or Se-containing species to form more electrophilic cationic or radical intermediates which participate in subsequent coupling reactions. It is anticipated that this review summarizes all C–S and C-Se bonds forming reactions enabled by hypervalent iodine reagents under metal-free conditions.