Applications Of Iodobenzene Dichloride And Its Analogues In Oxidative Transformation Of Alcohols Or Aldehydes

A highly efficient 2,2,6,6-tetramethylpiperidin-1-yloxy (TEMPO) catalyzed alcohol oxidation system using recyclable 1-chloro-1,2-benziodoxole-3(1H)-one (compound A) as the terminal oxidant in ethyl acetate (EtOAc) which is an environmentally friend organic solvent at room temperature has been developed. A variety of alcohols can be oxidized to their corresponding carbonyl compounds in high to excellent yields. Various heteroaromatic rings and C-C double bond are well tolerated under the reaction conditions. Compound A can be easily recycled after simple solid/liquid-phase separation and the subsequent regeneration sequence. In addition, a safe, very convenient, large scalable and high yielding procedure for the preparation of compound A from 2-iodobenzoic acid has been developed with sodium chlorite (NaClO2) as the stoichiometric oxidant in dilute hydrochloric acid at room temperature.Various aliphatic and aromatic aldehydes are converted into their corresponding carbamoyl azides in good to excellent yields with the use of a combined reagent system of iodobenzene dichloride (PhICl2) and sodium azide (NaN3) in CH3CN under nitrogen. Furthermore, PhICl2-NaN3 serves as the combined reagent system for "one-pot" effective synthesis of carbamoyl azides directly from primary alcohols. In addition, the same regent combination was also efficient for the oxidation of secondary alcohols to the corresponding ketones.Benzylic primary alcohols could be directly converted into symmetric 1,3-diarylureas or substituted benzamides via one-pot oxidative transformations using the combined reagent of PhI(OAc)2-NaN3 In addition, it was also found that various secondary alcohols could be readily oxidized to their corresponding ketones in excellent yields using the same PhI(OAc)2-NaN3 system.