An efficient and practical method for synthesis of C2‐phosphorylated indoles has been disclosed via a metal‐free 1,2‐phosphorylation of 3‐indolylmethanols with H‐phosphine oxides or H‐phosphonates. This alternative protocol features a broad substrate scope with respect to both 3‐indolylmethanols derived from isatins, acyclic α‐keto amide, α‐keto ester, 1,2‐diketone and simple ketones and H‐phosphine
3-Hydroxy-3-((3-methyl-4-nitroisoxazol-5-yl)methyl)indolin-2-one as a versatile intermediate for retro-Henry and Friedel–Crafts alkylation reactions in aqueous medium
retro-Henry type reaction is reported using 3-hydroxy-3-((3-methyl-4-nitroisoxazol-5-yl)methyl)indolin-2-ones which are prepared via catalyst-free Henry reaction of 3,5-dimethyl-4-nitroisoxazole and isatin. These compounds were used for the selective synthesis of 3-hydroxy-indolyl-2-oxindoles and bis-indolyl-2-oxindoles (symmetric/unsymmetric) via retro-Henry type reaction followed by Friedel–Crafts alkylation
Kaolin/KOH Is an Efficient Heterogeneous Catalyst for the Synthesis of 3-Hydroxy-3-indolyl Oxindoles
作者:G. Srihari、M. Marthanda Murthy
DOI:10.1080/00397911.2010.515342
日期:2011.9.15
3-Hydroxy-3-indolyl oxindoles were synthesized from isatins and indoles in good to excellent yields by using heterogeneous catalyst kaolin preloaded with KOH.
Synthesis of 3-ethynyl-3-hydroxy-2-oxindoles and 3-hydroxy-3-(indol-3-yl) indolin-2-ones using CuWO4 nanoparticles as recyclable heterogeneous catalyst in aqueous medium
acetylenes (spC-H activation) and selective synthesis of 3-hydroxy-3-(indol-3-yl) indolin-2-ones and 3,3′-bis(indolyl)indolin-2-ones (via Friedel-Crafts alkylation reaction) is reported in presence of CuWO4 (10 mol%) nanoparticles in aqueous medium. The catalyst was regenerated and reused up to 6 cycles without losing catalytic activity. This is the first report for the spC-H activation using CuWO4
Enantioselective Organocatalytic Addition of Nitroalkanes to Oxindolylideneindolenines for the Construction of Chiral 3,3-Disubstituted Oxindoles
作者:Jian-Zhou Huang、Xiang Wu、Liu-Zhu Gong
DOI:10.1002/adsc.201300373
日期:2013.9.16
An enantioselectiveorganocatalyticaddition of nitroalkanes to oxindolylideneindolenines in the presence of bifunctional organocatalysts has been established to provide an efficient entry to 3,3‐disubstituted oxindole derivatives in high yields and with excellent enantioselectivities. The transformation has been applied to the preparation of the key intermediate for a formal total synthesis of (+)‐gliocladin