Type I ‘Lighted Metal‐free’ Photosensitizing Assemblies of Phenazine for Aerobic Oxidative Transformations

Abstract

Highly photostable supramolecular photosensitizing 'lighted metal-free' assemblies of DPZ-Th have been developed which show strong absorption in the visible region and excellent electron transportation potential from donor to acceptor units. The as-prepared assemblies of DPZ-Th activate aerial oxygen to generate Type I reactive oxygen species (ROS) under visible-light irradiation in mixed aqueous media. Owing to these properties, the as-prepared DPZ-Th assemblies exhibit high photocatalytic activity in catalyzing the aerobic oxidative coupling of benzylamines and synthesis of quinazolines. Various spectroscopic studies support the participation of Type I reactive species in the reaction mechanism. The 'pure' oxygen environment was not needed for carrying out these transformations and all the reactions proceed very well under aerial conditions to furnish the desired products in high yields.

Thiadiazole-functionalized metal–organic frameworks for photocatalytic C–N and C–C coupling reactions: tuning the ROS generation efficiencyviacobalt introduction

“…On the basis of the above results and previous reports, 13,35,54–58 plausible mechanisms for the three aerobic oxidation reactions were proposed. First, we studied the role of the reactive oxygen species in these photocatalytic processes.…”

One‐pot synthesis of quinazolinones and quinazolines under visible light via decarboxylation of α‐hydroxy acids

“…For the other photocatalysts, only a small amount of product was received. Thereafter, the amount of [Acr-Mes] + (ClO 4 ) À was varied from 1 mol % to 5 mol% for the model reaction (Table 1, entries [8][9][10][11]. The highest yield was obtained when the amount of photocatalyst was 4 mol%.…”

“…The traditional methods for the synthesis of quinazoline and quinazolinone are based on 2-aminobenzamide, 2-aminobenzylamine, and aldehydes [10][11][12][13][14]. However, aldehydes cannot be easily stored or transported and are easy to be oxidized and deteriorated.…”

Recent advances in type I organic photosensitizers for efficient photodynamic therapy for overcoming tumor hypoxia

“…89 For instance, Lovjot Kaur et al reported a pyrazine-based supramolecular photosensitizer, which had electron transfer ability and generated superoxide radicals through the type I pathway. 90 Cheng and colleague prepared a self-assembled supramolecular nanophotosensitizer for enhanced ROS generation by promoting type I photoreaction. 91 Yoon and co-workers reported phthalocyanines with electron-donating amine groups as type I supramolecular PSs (SPSs) by self-assembly.…”