Brønsted Base-Catalyzed Enantioselective α-Functionalization of Carbonyl Compounds Involving π-Extended Enolates |
| |
Authors: | Prof Mikel Oiarbide Prof Claudio Palomo |
| |
Institution: | Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018 San Sebastián Spain |
| |
Abstract: | Chiral Brønsted base (BB) catalyzed asymmetric transformations constitute an important tool for synthesis. A meaningful fraction of these transformations proceeds through transiently generated enolate intermediates, which display quite versatile reactivity against a variety of electrophiles. Some years ago, our group became interested in developing BB-catalyzed asymmetric reactions of enolizable carbonyl substrates that involve π-extended enolates in which, besides control of reaction diastereo and enantioselectivity, the site-selectivity control is an additional issue in most cases. In the examples covered in this account the opportunities deployed, and the challenges posed, by these methods are illustrated, with a focus on the generation of quaternary carbon stereocenters. In the way, new bifunctional BB catalysts as well as achiral templates were developed that may find further applications. |
| |
Keywords: | asymmetric catalysis bifunctional catalysis extended enolates quaternary stereocenters regioselectivity |
|
|