http://hdl.handle.net/10045/2396 Fri, 24 May 2013 03:42:30 GMT 2013-05-24T03:42:30Z http://hdl.handle.net/10045/25968 Título: Asymmetric aldol reaction with BINAM-sulfonyl polymeric organocatalyst Autor/es: Bañón Caballero, Abraham; Guillena Townley, Gabriela; Nájera Domingo, Carmen Resumen: The BINAM-sulfonyl polymeric organocatalysts was prepared by the AIBN-promoted copolymerization of BINAM-derived sulfonamide, styrene and divinylbenzebe. The polymer catalyzed the asymmetric aldol reaction of aliphatic ketones with aromatic aldehydes to give the aldol products in up to 83% yield and with up to 95% ee. The catalysts could be recovered upt to 6 times with only a slight decrease on its activity. Mon, 17 Dec 2012 00:00:00 GMT http://hdl.handle.net/10045/25968 2012-12-17T00:00:00Z http://hdl.handle.net/10045/23276 Título: Enantioselective direct aldol reaction of α-keto esters catalyzed by (Sa)-binam-D-prolinamide under quasi solvent-free conditions Autor/es: Viózquez Cámara, Santiago Fidel; Bañón Caballero, Abraham; Guillena Townley, Gabriela; Nájera Domingo, Carmen; Gómez Bengoa, Enrique Resumen: (Sa)-Binam-D-prolinamide (20 mol%), instead of (Sa)-binam-L-prolinamide, in combination with chloroacetic acid (100 mol%) is an efficient organocatalyst for the direct aldol reaction between α-keto esters as electrophiles and alkyl and α-functionalised ketones, under quasi solvent-free conditions, providing access to highly functionalised chiral quaternary γ-keto α-hydroxyesters with up to 92% ee. Fri, 23 Mar 2012 00:00:00 GMT http://hdl.handle.net/10045/23276 2012-03-23T00:00:00Z http://hdl.handle.net/10045/16905 Título: Recent advances on the organocatalyzed enantioselective α-heterofunctionalization of carbonyl compounds Autor/es: Guillena Townley, Gabriela; Ramón Dangla, Diego José Resumen: This review covers literature on organocatalyzed enantioselective a-heterofunctionalization of carbonyl compounds from 2006 to 2009. In this review, we will consider those reactions in which a new carbon-heteroatom bond is formed using α chiral organic molecule as catalyst, excluding those processes, which involve the modification on the hybridization of a previously functionalized carbonyl compound. Using this straightforward synthetic strategy, a wide range of valuable chiral building blocks such as α-amino acids, α-amino alcohols, epoxides, 1,2-diols, α-sulfenylated, α-selenenylated and α-halogenated carbonyl derivatives can be obtained by this simple and advantageous methodology. Tue, 01 Feb 2011 00:00:00 GMT http://hdl.handle.net/10045/16905 2011-02-01T00:00:00Z http://hdl.handle.net/10045/16189 Título: (S)-Binam-L-prolinamide as organocatalyst for the enantioselective conjugate addition of α-alkoxyketones to β-nitrostyrene derivatives Autor/es: Guillena Townley, Gabriela; Nájera Domingo, Carmen; Viózquez Cámara, Santiago Fidel; Yus Astiz, Miguel Resumen: (S)-Binam-L-prolinamide (20 mol%) catalyze the enantioselective Michael addition of several α-alkoxyketones to different β-nitrostyrene derivatives. In the study of the optimization of the reaction conditions it was found surprisingly that hexane is the solvent of choice to carry out such transformation. Under these reaction conditions, the corresponding highly functionalized products were obtained in good yields (up to 90%), mainly as syn-diastereomers with moderate diastereo- and enantioselectivities. Fri, 04 Feb 2011 00:00:00 GMT http://hdl.handle.net/10045/16189 2011-02-04T00:00:00Z