Zinc Stabilized Azo-anion Radical in Dehydrogenative Synthesis of N-Heterocycles. An Exclusively Ligand Centered Redox Controlled Approach was written by Das, Siuli;Mondal, Rakesh;Chakraborty, Gargi;Guin, Amit Kumar;Das, Abhishek;Paul, Nanda D.. And the article was included in ACS Catalysis in 2021.SDS of cas: 1777-82-8 This article mentions the following:
Herein an exclusively ligand-centered redox controlled approach for the dehydrogenation of a variety of N-heterocycles such as 1,2,3,4-tetrahydro-2-methylquinoline, 1,2,3,4-tetrahydro-isoquinoline, indoline, 2-phenyl-2,3-dihydro-1H-benzoimidazole, 2,3-dihydro-2-phenylquinazolin-4(1H)-ones I (R = H, 2-Br, 4-Cl, 4-Me, etc.; X = C=O) and 1,2,3,4-tetrahydro-2-phenylquinazolines I (X = CH2) using a Zn(II)-stabilized azo-anion radical complexes II (R1 = H, Cl) as the catalyst was reported. A simple, easy to prepare and bench stable Zn(II)-complex III (R1 = Cl) featuring the tridentate arylazo pincer, 2-((4-chlorophenyl)diazenyl)-1,10-phenanthroline, in the presence of zinc-dust, undergoes reduction of azo-anion radical species II (R1 = Cl) which efficiently dehydrogenates various saturated N-heterocycles such as 1,2,3,4-tetrahydro-2-methylquinoline, 1,2,3,4-tetrahydro-isoquinoline, indoline, 2-phenyl-2,3-dihydro-1H-benzoimidazole, 2,3-dihydro-2-phenylquinazolin-4(1H)-ones I (X = C=O) and 1,2,3,4-tetrahydro-2-phenylquinazolines I (X = CH2) under air. The catalyst has further been found to be compatible with the cascade synthesis of these N-heterocycles IV (R2 = n-Bu, Ph, thiophen-2-yl, etc.; R3 = H, Me; R4 = H, Br, Me), V (R5 = H, Cl) and VI (R6 = H, Cl; R7 = H, Me; R8 = Ph, 2-fluorophenyl, pyridin-2-yl, etc.) via dehydrogenative coupling of alcs. R2CH2OH and 2-NH2-4-R6-C6H3CH2OH with other suitable coupling partners under air. Mechanistic investigation reveals that the dehydrogenation reactions proceed via a one-electron hydrogen atom transfer (HAT) pathway where the zinc-stabilized azo-anion radical ligand abstracts the hydrogen atom from the organic substrate(s), and the whole catalytic cycle proceeds via the exclusive involvement of the ligand-centered redox events where the zinc acts only as the template. In the experiment, the researchers used many compounds, for example, (2,4-Dichlorophenyl)methanol (cas: 1777-82-8SDS of cas: 1777-82-8).
(2,4-Dichlorophenyl)methanol (cas: 1777-82-8) belongs to alcohols. Because alcohols are easily synthesized and easily transformed into other compounds, they serve as important intermediates in organic synthesis. Converting an alcohol to an alkene requires removal of the hydroxyl group and a hydrogen atom on the neighbouring carbon atom. Dehydrations are most commonly carried out by warming the alcohol in the presence of a strong dehydrating acid, such as concentrated sulfuric acid.SDS of cas: 1777-82-8
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts