1370034-82-4Relevant academic research and scientific papers
Histidine-catalyzed asymmetric aldol addition of enolizable aldehydes: Insights into its mechanism
Scheffler, Ulf,Mahrwald, Rainer
experimental part, p. 2310 - 2330 (2012/05/20)
Extensive studies of asymmetric cross-aldol addition between enolizable aldehydes are described and provide a deeper insight into histidine-catalyzed aldol additions. In particular, aspects of enantio- as well as diastereoselectivity of these reactions are discussed. Rules and predictions of configurative outcome are explained by using different transition-state models. These discussions are confirmed by extensive computations.
Stereoselectivities of histidine-catalyzed asymmetric aldol additions and contrasts with proline catalysis: A quantum mechanical analysis
Lam, Yu-Hong,Houk,Scheffler, Ulf,Mahrwald, Rainer
supporting information; experimental part, p. 6286 - 6295 (2012/05/07)
Quantum mechanical calculations reveal the origin of diastereo- and enantioselectivities of aldol reactions between aldehydes catalyzed by histidine, and differences between related reactions catalyzed by proline. A stereochemical model that explains both the sense and the high levels of the experimentally observed stereoselectivity is proposed. The computations suggest that both the imidazolium and the carboxylic acid functionalities of histidine are viable hydrogen-bond donors that can stabilize the cyclic aldolization transition state. The stereoselectivity is proposed to arise from minimization of gauche interactions around the forming C-C bond.
