Silica-supported sodium sulfonate with ionic liquid: a neutral catalyst system for Michael reactions of indoles in water.
A neutral catalytic system for Michael reactions of indoles has been developed by combining silica-supported benzenesulfonic acid sodium salt with hydrophobic ionic liquid in water. An efficient hydrophobic environment could be created on the surface of the silica-sodium material under the conditions. Various indole derivatives and alpha,beta-unsaturated carbonyl compounds including some acid-labile substrates were successfully applied to this system with water as the sole solvent to afford the desired Michael adducts in high yields. [structure: see text].
Gu
Yanlong
Y
Graduate School of Pharmaceutical Sciences, The University of Tokyo, The HFRE Division, ERATO, Japan Science and Technology Agency, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Ogawa
Chikako
C
Kobayashi
Shū
S
D001557:Benzenesulfonates / Q000737:chemistry*; D002384:Catalysis; D057927:Hydrophobic and Hydrophilic Interactions; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D015394:Molecular Structure; D012822:Silicon Dioxide / Q000737:chemistry*; D013237:Stereoisomerism; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D001557:Benzenesulfonates; D007211:Indoles; D052578:Ionic Liquids; D014867:Water; C032365:benzenesulfonic acid; D012822:Silicon Dioxide