A Bench-stable 8-Aminoquinoline Derived Phosphine-free Manganese (I)-Catalyst for Environmentally Benign C(α)-Alkylation of Oxindoles with Secondary and Primary Alcohols

Parul Saini; Pritam Dolui; Abhishek Nair; Ashutosh Verma; Anil J Elias

doi:10.1002/asia.202201148

A Bench-stable 8-Aminoquinoline Derived Phosphine-free Manganese (I)-Catalyst for Environmentally Benign C(α)-Alkylation of Oxindoles with Secondary and Primary Alcohols

Chem Asian J. 2023 Mar 14;18(6):e202201148. doi: 10.1002/asia.202201148. Epub 2023 Feb 6.

Authors

Parul Saini¹, Pritam Dolui¹, Abhishek Nair¹, Ashutosh Verma¹, Anil J Elias¹

Affiliation

¹ Department of Chemistry, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, 110016, India.

PMID: 36688923
DOI: 10.1002/asia.202201148

Abstract

Herein, we report a new air-stable phosphine-free 8-AQ (8-aminoquinoline) based Mn(I) carbonyl complex as the catalyst for the C(α)-alkylation of oxindoles with alcohols. The Mn complex [(8-AQ)Mn(CO)₃ Br] works effectively as a catalyst for the α-alkylation of oxindoles by both secondary as well as primary alcohols. The procedure has been used for the synthesis of pharmaceutically important recently developed oxindoles such as 3-(4-methoxybenzyl)indolin-2-one, 3-(4-(dimethylamino)benzyl)indolin-2-one, 3-(4-(dimethylamino)phenyl)-5-fluoroindolin-2-one and 3-(benzo[d][1,3]dioxol-5-ylmethyl)indolin-2-one, which are found to be effective in preventing specific types of cell death in neurodegenerative disorders. Control experiments have been carried out to investigate the reaction mechanism and the crucial role of metal-ligand cooperation via -NH₂ moiety during catalysis.

Keywords: C(α)-alkylation; manganese; oxindole; phosphine-free; secondary alcohol.

Abstract

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