Guillena, Gabriela, Hita López, María del Carmen, Nájera, Carmen Highly selective direct aldol reaction organocatalyzed by (S)-BINAM-L-prolinamide and benzoic acid using α-chalcogen-substituted ketones as donors GUILLENA TOWNLEY, Gabriela; HITA, María del Carmen; NÁJERA DOMINGO, Carmen. "Highly selective direct aldol reaction organocatalyzed by (S)-BINAM-L-prolinamide and benzoic acid using α-chalcogen-substituted ketones as donors". ARKIVOC 2007 (IV). ISSN 1424-6376, pp. 260-269 URI: http://hdl.handle.net/10045/2577 DOI: ISSN: 1424-6376 Abstract: Recoverable (S)-BINAM-L-prolinamide in combination with benzoic acid catalyzes and accelerates the direct aldol reaction between several α-chalcogen-substituted ketones and pnitrobenzaldehyde in different solvents, including water. Choosing conveniently the aldol donor, solvent and conditions, it is possible to obtain mainly one of the two possible regioisomers with good diastero- and enantioselectivity. Thus, α-hydroxy and α-alkoxyacetones give mainly syn/anti regioisomers, whereas α-(methylsulphanyl)acetone affords the iso-aldol in 93% ee. In the case of α-hydroxy and α-methoxyacetone the anti diasteromer is obtained with up to 84% ee. However, α-benzyloxyacetone yields mainly the syn-diasteroisomer in 85% ee. Keywords:Organocatalysis, Aldol, Enantioselective, Asymmetric synthesis, Amino acids, Proline, Diols Arkat USA, Inc. info:eu-repo/semantics/article