Asymmetric Epoxidation Using Iminium Salt Organocatalysts Featuring Dynamically Controlled Atropoisomerism

PC Bulman Page, CJ Bartlett, Y Chan…

Index: Bulman Page, Philip C.; Bartlett, Christopher J.; Chan, Yohan; Day, David; Parker, Phillip; Buckley, Benjamin R.; Rassias, Geracimos A.; Slawin, Alexandra M. Z.; Allin, Steven M.; Lacour, Jerome; Pinto, Andre Journal of Organic Chemistry, 2012 , vol. 77, # 14 p. 6128 - 6138

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Citation Number: 21

Abstract

Introduction of a pseudoaxial substituent at a stereogenic center adjacent to the nitrogen atom in binaphthyl-and biphenyl-derived azepinium salt organocatalysts affords improved enantioselectivities and yields in the epoxidation of unfunctionalized alkenes. In the biphenyl-derived catalysts, the atropoisomerism at the biphenyl axis is controlled by the interaction of this substituent with the chiral substituent at nitrogen.