Molecular Iodine Catalysed Benzylic sp3 C–H Bond Amination for the Synthesis of 2-Arylquinazolines from 2-Aminobenzaldehydes, 2-Aminobenzophenones and 2-Aminobenzyl Alcohols

Abstract

Molecular iodine catalysed benzylic sp3 C–H bond amination has been developed for the synthesis of quinazolines from 2-aminobenzaldehydes and 2-aminobenzophenones with benzylamines. The use of oxygen as a green oxidant combined with the transition-metal-, additive- and solvent-free conditions makes the methodology economical and greener. The lack of aqueous work up also enhances the efficiency of this protocol. A series of 2-arylquinazolines was synthesised in good to excellent yields by using the developed protocol. 2-Amino­benzyl alcohols could also be employed to prepare the corresponding quinazoline derivatives.

Greener synthesis of chemical compounds and materials

“…6: 191378 3. Green synthesis of organic, labelled and hybrid compounds A host of organic synthesis reactions, considered by authors as green processes, have been recently reviewed [1,64,65]. So, here we briefly mention the most representative recent examples of ecofriendly organic reactions, which fit to the 12 green chemistry rules.…”

“…use of molecular O 2 in C-H bond amination without solvents, metals and additives [64]; five times reuse of the catalyst in the reaction of aryl bromides and arylboronic acids [79]; use of water-tolerant Lewis acid ZrO(NO 3 ) 2 catalyst for cyclization of o-aminochalcones [70]; use of cheap carbonyl Fe powder [71]; high-yield short-time solvent-free reactions [72];…”

“…We note that several compounds above are industrially important, for example, hydroquinone or PC. Indeed, a variety of particular objectives and goals can be reached by greener methods, in particular: use of molecular O 2 in C–H bond amination without solvents, metals and additives [64];five times reuse of the catalyst in the reaction of aryl bromides and arylboronic acids [79];use of water-tolerant Lewis acid ZrO(NO 3 ) 2 catalyst for cyclization of o -aminochalcones [70];use of cheap carbonyl Fe powder [71];high-yield short-time solvent-free reactions [72];bubbling with H 2 without autoclave [73];high-yield synthesis of NHPI esters in water [80];use of commercial montmorillonite K10 as a catalyst [81]; anduse of cheap H 2 O 2 as oxidant [82]. In addition to classic organic molecules, a review [1] is dedicated to the green synthesis of ‘inorganic–organic hybrid materials', consisting of an organic (polymer) matrix containing inorganic building blocks (1–10 3 nm).…”

Chemical Insights Into the Synthetic Chemistry of Quinazolines: Recent Advances

“…Very recently, Bhanage et al reported the preparation of I 2 -catalyzed quinazoline derivatives 29 from reaction of 2-aminobenzaldehydes 28 or 2-aminobenzophenones with benzyl-amines 27 (Scheme 12). Numerous functionalized hetero-aryl or aryl amines were investigated with an ample range of functionalized 2-aminobenzaldehydes or 2aminobenzophenones 28 to give the quinazolines 29 in moderate to excellent yields (49-92%) (Deshmukh and Bhanage, 2018). The application of O 2 as an eco-friendly oxidant coupled with the solvent-, additive-and transition-metal-free conditions makes the approach greener and economical.…”

Titanium Tetraiodide/Trimethylsilyl Iodide Synergistically Induced Cyclization of N-(2-Cyanophenyl)benzamides into 2-Aryl-4-iodoquinazolines

“…15 Bhanage reported molecular-iodine-catalyzed benzylic sp 3 C–H bond amination for the synthesis of 2-arylquinazolines from 2-aminobenzaldehydes, 2-aminobenzophenones, and 2-aminobenzyl alcohols. 16…”