Oxidative decarboxylative ammonium hypoiodite-catalysed dihydrobenzofuran synthesis

The catalytic use of quaternary ammonium iodides under oxidative conditions allows for the direct conversion of readily available β-ketolactones into dihydrobenzofurans via a decarboxylative oxidative cycloetherification sequence facilitated by an in situ formed ammonium hypoiodite species.

One-pot synthesis of 1,3,4-oxadiazol-2(3H)-ones with CO2 as a C1 synthon promoted by hypoiodite

A convenient and efficient route has been developed to synthesize 1,3,4-oxadiazol-2(3H)-ones from CO₂, hydrazines and aryl or aliphatic aldehydes. Promoted by hypoiodite (IO^-) generated in situ from KI and oxidant TBHP, the one-pot synthesis could proceed smoothly to afford the desired products in moderate to high yields. Mechanism studies revealed that nitrile imine was an important intermediate in this transformation. Notably, a commercial herbicide Oxadiazon could be successfully synthesized by this route.

Cooperative iodine and photoredox catalysis for direct oxidative lactonization of carboxylic acids

C–H lactonization is enabled by visible light-promoted cooperative catalysis combining molecular iodine and an organic dye.

α-Acetoxyarone synthesis via iodine-catalyzed and tert-butyl hydroperoxide-mediateded self-intermolecular oxidative coupling of aryl ketones

We present a metal-free method for α-acetoxyarone synthesis by self-intermolecular oxidative coupling of aryl ketones using I₂−tert-butyl hydroperoxide (TBHP). Under the optimum conditions, various aryl ketones gave the corresponding products in moderate to excellent yields. A series of control experiments were performed; the results suggest the involvement of radical pathways. Multiple radical intermediates were generated in situ and the overall process involved several different reactions, which proceeded self-sequentially in a single reactor. A labeling experiment using ¹⁸O-labeled H₂O confirmed that the oxygen in the product was derived from TBHP, not from H₂O in the TBHP solvent.

KI-catalyzed α-acyloxylation of acetone with carboxylic acids

A KI catalyzed reaction of acetone with aromatic carboxylic acids is achieved, leading to α-acyloxycarbonyl compounds in good to excellent yields under mild reaction conditions. The present method exhibits good functional-group compatibility.

Hypoiodite-catalysed oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds: a facile and versatile approach to substituted furans and cyclopropanes

Hypoiodite catalysis for selective oxidative cyclization has been developed, yielding either furans or cyclopropanes with excellent diastereoselectivity.