151920-47-7Relevant academic research and scientific papers
Sodium tetramethoxyborate: An efficient catalyst for Michael additions of stabilized carbon nucleophiles
Campana, Araceli G.,Fuentes, Noelia,Gomez-Bengoa, Enrique,Mateo, Cristina,Oltra, J. Enrique,Echavarren, Antonio M.,Cuerva, Juan M.
, p. 8127 - 8130 (2007)
(Chemical Equation Presented) Sodium tetramethoxyborate, easily prepared by reaction of inexpensive sodium borohydride with methanol, possesses a suitable combination of a Lewis base and a Lewis acid to catalyze Michael reactions at room temperature under
Phosphine-boronates: Efficient bifunctional organocatalysts for Michael addition
Basle, Olivier,Porcel, Susana,Ladeira, Sonia,Bouhadir, Ghenwa,Bourissou, Didier
supporting information; experimental part, p. 4495 - 4497 (2012/05/31)
Phosphine-boronates R2P(o-C6H4) B(OR′)2 have been evaluated as bifunctional organocatalysts for the Michael addition of malonate pronucleophiles to methylvinylketone. The presence of the Lewis acidic boron center adjacent to phosphorus significantly improves catalytic performance. Isolation and complete characterization of a key intermediate, namely a β-phosphonium enolate, substantiate the role of the Lewis acidic moiety in the catalytic process.
Michael reaction of stabilized carbon nucleophiles catalyzed by [RuH2(PPh3)4]
Gómez-Bengoa, Enrique,Cuerva, Juan M.,Mateo, Cristina,Echavarren, Antonio M.
, p. 8553 - 8565 (2007/10/03)
The Michael reaction of active methylene compounds lacking cyano groups such as malonates, β-ketoesters, 1,3-diketones, 1,1-disulfones, nitrocompounds, Meldrum acid, and anthrone with common acceptors proceeds in acetonitrile solution in the presence of [RuH2(PPh3)4] as the catalyst. Cyano acetates, more acidic than malonates in organic solvents, are also excellent substrates for this reaction. In a number of cases, intramolecular aldol reactions catalyzed by [RuH2(PPh3)4] were also observed as side reactions. Catalysis by other ruthenium and rhodium complexes has been examined. Selectivity studies performed with malonate and disulfone donors indicate that the catalyst selectively activates Michael donors that can coordinate with ruthenium(II). Additionally, it has been shown that the reaction requires the presence of free phosphine. Therefore, the Michael reaction of stabilized enolates appears to be a ruthenium- and phosphine-catalyzed reaction. From a practical point of view, the use of readily prepared [RuH2(PPh3)4] as the catalyst in acetonitrile provided the best solution for the Michael reaction of active methylene compounds.
