A Facile Method for the Synthesis of 3-Alkyloxindole
作者:Tai-Ping Du、Gang-Guo Zhu、Jian Zhou
DOI:10.2174/157017812800167420
日期:2012.3.1
Benzylamine in combination with acetic acid was identified as a powerful catalyst for the condensation of oxindole with aldehydes, acetone or cyclic ketones. A variety of 3-alkyloxindoles could be readily prepared in 10 mmol scale via the sequential benzylamine acetate catalyzed condensation of oxindoles with aldehydes (or ketones) and conjugate reduction by NaBH4.
We report the development of a rapid approach for directly converting indoles into 2-oxindoles promoted by HOCl formed in situ from the combination of (bis(trifluoroacetoxy) iodo)benzene (PIFA) and n-Bu4NCl ⋅ H2O. The procedure is widely functional group tolerant and provides 2-oxindoles in up to 95% yield within 5 min. The potential applications of the developed methodology are demonstrated by the
Photochemical Deracemization of 3‐Substituted Oxindoles
作者:Johannes Großkopf、Alexandra A. Heidecker、Thorsten Bach
DOI:10.1002/anie.202305274
日期:2023.7.24
A benzophenone-based catalyst was used as the only source of chirality in the photochemical deracemization of 3-substituted oxindoles. The reaction likely proceeds by hydrogen atom transfer and delivers the desired products, and derivatives thereof, with high enantiomeric excess.
A Bench‐stable 8‐Aminoquinoline Derived Phosphine‐free Manganese (I)‐Catalyst for Environmentally Benign C(α)‐Alkylation of Oxindoles with Secondary and Primary Alcohols
作者:Parul Saini、Pritam Dolui、Abhishek Nair、Ashutosh Verma、Anil J. Elias
DOI:10.1002/asia.202201148
日期:2023.3.14
air-stable, phosphine-free 8-aminoqunoline (8-AQ) based Mn(I) carbonyl complex as the catalyst for the C(α)-alkylation of oxindoles with alcohols has been developed. The Mn complex [(8-AQ)Mn(CO)3Br] works effectively as a catalyst for α-alkylation of oxindoles by both secondary as well as primary alcohols. Few pharmaceutically relevant compounds were also synthesized by this method in good yields.