Visible-Light-Induced Oxidative Coupling of Phenols and Alkenylphenols with a Recyclable, Solid Photocatalyst

Abstract

A photocatalytic method for phenol and alkenylphenol oxidative coupling is reported using an inexpensive heterogeneous titanium dioxide photocatalyst with air and visible light. During the coupling process, the Ti−substrate complex is activated under visible light through a ligand to metal charge transfer effect, and the diphenol adduct is proposed to form through a radical cation. The heterogeneous TiO 2 catalyst remains stable throughout the reaction and can be easily removed and reused multiple times.

Allylation of C‐, N‐, and O‐Nucleophiles via a Mechanochemically‐Driven Tsuji–Trost Reaction Suitable for Late‐Stage Modification of Bioactive Molecules

“…Phenylhydrazine was exclusively allylated at the N 1 -position, consistent with recent literature reports [23] (product 28). The sulfonamide moiety in Celecoxib was fully bis-allylated as its high nucleophilicity hampers a monoselective reaction (36). This mild protocol successfully facilitated the allylation of several complex N-containing small molecule drugs (30)(31)(32)(33)(34)(35)(36), highlighting its potential in late-stage modifications.…”

Recent advances in oxidative phenol coupling for the total synthesis of natural products

“…A recent publication from the Kozlowski group detailed a photochemical oxidative coupling of phenols and alkenyl phenols using a heterogenous TiO 2 catalyst for the formation of the aforementioned natural products licarin A (37) and carpanone (39). 142…”

Allylation of C‐, N‐, and O‐Nucleophiles via a Mechanochemically‐Driven Tsuji–Trost Reaction Suitable for Late‐Stage Modification of Bioactive Molecules

“…The authors have cited additional references within the Supporting Information. [ 20 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]…”