899795-63-2Relevant academic research and scientific papers
Asymmetric cooperative catalysis of strong bronsted acid-promoted reactions using chiral ureas
Xu, Hao,Zuend, Stephan J.,Woll, Matthew G.,Tao, Ye,Jacobsen, Eric N.
scheme or table, p. 986 - 990 (2010/10/03)
Cationic organic intermediates participate in a wide variety of useful synthetic transformations, but their high reactivity can render selectivity in competing pathways difficult to control. Here, we describe a strategy for inducing enantioselectivity in reactions of protio-iminium ions, wherein a chiral catalyst interacts with the highly reactive intermediate through a network of noncovalent interactions. This interaction leads to an attenuation of the reactivity of the iminium ion and allows high enantioselectivity in cycloadditions with electron-rich alkenes (the Povarov reaction). A detailed experimental and computational analysis of this catalyst system has revealed the precise nature of the catalyst-substrate interactions and the likely basis for enantioinduction.
