673491-75-3Relevant academic research and scientific papers
Recoverable silica-gel supported binam-prolinamides as organocatalysts for the enantioselective solvent-free intra- and intermolecular aldol reaction
Ba?ón-Caballero, Abraham,Guillena, Gabriela,Nájera, Carmen,Faggi, Enrico,Sebastián, Rosa María,Vallribera, Adelina
, p. 1307 - 1315 (2013/02/23)
Silica-gel supported binam-derived prolinamides are efficient organocatalysts for the direct intramolecular and intermolecular aldol reaction under solvent-free conditions using conventional magnetic stirring. These organocatalysts in combination with benzoic acid showed similar results to those obtained under similar homogeneous reaction conditions using an organocatalyst of related structure. For the intermolecular process, the aldol products were obtained at room temperature and using only 2 equiv of the ketone with high yields, regio-, diastereo- and enantioselectivities. Under these reaction conditions, also the cross aldol reaction between aldehydes is possible. The recovered catalyst can be reused up to nine times providing similar results. More interestingly, these heterogeneous organocatalysts can be used in the intramolecular aldol reaction allowing the synthesis of the Wieland-Miescher and ketone analogues with up to 92% ee, with its reused being possible up to five times without detrimental on the obtained results.
Solvent-free direct enantioselective aldol reaction using polystyrene-supported N-sulfonyl-(Ra)-binam-d-prolinamide as a catalyst
Banon-Caballero, Abraham,Guillena, Gabriela,Najera, Carmen
experimental part, p. 1599 - 1606 (2010/12/25)
The immobilization of N-sulfonyl-(Ra)-binam-d-prolinamide using polystyrene as a support allows the recovery of an efficient catalytic system for the enantioselective direct aldol reaction between different ketones and aldehydes under solvent-f
N-Tosyl-(Sa)-binam-L-prolinamide as highly efficient bifunctional organocatalyst for the general enantioselective solvent-free aldol reaction
Guillena, Gabriela,Nájera, Carmen,Viózquez, Santiago F.
experimental part, p. 3031 - 3035 (2009/10/16)
N-Tosyl-(Sa)-binam-L-prolinamide (5 mol%) and benzoic acid (1 mol%) were used as catalysts in the enantioselective direct aldol reaction between different ketones and aldehydes under solvent-free conditions in the presence or absence of water. Under these reaction conditions it was possible to reduce the amount of required ketone to two equivalents to give the corresponding aldol products with high yields, regio-, diastereo- and enantioselectivities. The aldol reaction between aldehydes or the intramolecular aldol reaction can be also performed with excellent results. Georg Thieme Verlag Stuttgart.
Highly stereoselective direct aldol reactions catalyzed by (S)-NOBIN-l-prolinamide
Russo, Alessio,Botta, Giovanna,Lattanzi, Alessandra
, p. 11886 - 11892 (2008/03/13)
(S)-NOBIN-l-prolinamide was employed as organocatalyst in the direct aldol reactions of different ketones and aromatic aldehydes using dioxane as solvent and in the presence of water as additive. Acetone led to the aldol products in up to 93% ee, while cy
Unusual reversal of regioselectivity in antibody-mediated aldol additions with unsymmetrical methyl ketones
Maggiotti,Bahmanyar,Reiter,Resmini,Houk,Gouverneur
, p. 619 - 632 (2007/10/03)
A catalytic regio- and enantioselective aldol reaction of various unsymmetrical methyl ketones with para-nitrobenzaldehyde has been developed using aldolase antibodies as the catalysts. It has been found that the sense and level of regioselectivity for the reactions catalysed by antibody 38C2 and 33F12 are highly dependent on the structure of both the donor and the acceptor but in contrast, antibodies 84G3 and 93F3 catalyse the exclusive formation of the linear regioisomer independent of the structure of the reactants examined. The level of enantiocontrol is very high for most reactions. Both linear aldol enantiomers could be accessed through aldol or retro-aldol reactions using the same antibody. Theoretical studies on regioisomeric α- and β-heteroatom substituted enamines derived from unsymmetrical ketones suggest that most of the linear aldol products formed in the presence of antibodies 84G3 and 93F3 must be formed from intermediate enamines which are not the thermodynamically most favourable.
