Fe(III)‐Catalyzed Aerobic Oxidation of 1,4‐Diols^†

Abstract

Comprehensive Summary Aerobic oxidation has been catching more and more attention because of its atom economy and environmental friendliness. Oxidation of diols is a challenge due to various oxidative products. Thus, highly selective aerobic oxidation affording specific products is of current interest. In this work, a combination of Fe(NO3)3·9H2O/TEMPO/KCl catalysis has been identified as an efficient recipe for the aerobic oxidation of 1,4‐diols affording γ‐butyrolactones under mild conditions. The reaction exhibits decent chemo‐ and regioselectivity of symmetrical and unsymmetrical 1,4‐diols. The optically active γ‐lactones may also be prepared from optically active 1,4‐diols without erosion of the ee via this method. Furthermore, this approach was successfully applied to synthesize NBP, a commercial drug.

Alternative method to Baeyer–Villiger oxidation of cyclobutenones using I2/DMSO catalytic systems

“…2 As a result, numerous methods have been developed for lactone synthesis. 3 Among these methods, Baeyer–Villiger oxidation has proven to be an efficient protocol for the preparation and industrial production of lactones (Scheme 2a). 4 Consequently, various oxidants and catalysts, including peroxyacids, have been developed to facilitate this transformation.…”

Relay Catalysis for Selective Aerobic Oxidative Esterification of Primary Alcohols with Methanol

“…Based on our hypothesis, the oxidative esterification of cetyl alcohol 1a with a series of different alcohols was conducted (Table ). After tedious screening, BiCl 3 has been identified as the potential cocatalyst together with Fe­(NO 3 ) 3 ·9H 2 O and TEMPO for such a target transformation . As reported, the reaction of 1a with benzyl alcohol 2a afforded the corresponding aldehydes 3a / 8a and the self-esterification product 5a / 10a , (Table , entry 1); with n -BuOH, 51% of palmitaldehyde 3a and 32% of butyraldehyde 8b were obtained with 11% of recovery of 1a .…”