Highly efficient heterogeneous V₂O₅@TiO₂ catalyzed the rapid transformation of boronic acids to phenols

Abstract

A V2O5@TiO2 catalyzed green and efficient protocol for the hydroxylation of boronic acid into phenol has been developed utilizing environmentally benign oxidant hydrogen peroxide. A wide range of electron‐donating and the electron‐withdrawing group‐containing (hetero)aryl boronic acids were transformed into their corresponding phenol. The methodology was also applied successfully to transform various natural and bioactive molecules like tocopherol, amino acids, cinchonidine, vasicinone, menthol, and pharmaceuticals such as ciprofloxacin, ibuprofen, and paracetamol. The other feature of the methodology includes gram‐scale synthetic applicability, recyclability, and short reaction time.

Heterogeneous V2O5/TiO2-Mediated Photocatalytic Reduction of Nitro Compounds to the Corresponding Amines under Visible Light

“…Initially, the catalyst screening is performed with V 2 O 5 /TiO 2 catalysts, i.e., C-05, C-10, C-20, and C-30, containing variable V 2 O 5 contents of 5, 10, 20, and 30% supported over TiO 2 , respectively (Figure ). It was observed that C-05 and C-10 catalyst gives low yields (Table , entries 1–2). Thus, out of these four catalysts, C-20 and C-30 were suitable for this transformation as they gave a high yield and required a shorter reaction time compared to C-05 and C-10 catalysts (Table , entries 3–4).…”

Copper(II) NHC Catalyst for the Formation of Phenol from Arylboronic Acid

“…Together, these catalytic observations give a clear indication of the conditions for generating phenol from the activation of arylboronic acids using the reported copper(II) NHC complex in water. This C-O bond forming reaction has been shown to have significant merit on its own [23,[41][42][43][44][45][46], but it also provides insight into conditions where phenol generation is limited. C-O bond formation occurs in a similar pathway to other CEL bond forming processes but requires higher energy conditions (high temperature) and carefully controlled pH.…”

Late-stage modification of bioactive compounds: Improving druggability through efficient molecular editing

“…Shi group transferred aryl borides to phenols with trichloroacetonitrile as an activator under blue LED, and steride derivatives underwent this condition 228 . Another work of converting aryl borides to phenols was reported by Maurya, and many bioactive molecules could be late-stage hydroxylated ( Scheme 14 b) 229 . Jiao and coworkers used DMSO as an oxygen source to transfer simple organobromides or olefins to bromohydrins, and the hydroxybromination of (+)- δ -tocopherol derivative underwent to produce the corresponding product ( Scheme 14 c) 230 .…”