184046-33-1Relevant articles and documents
Asymmetric Epoxidation of Unfunctionalized Olefins Using Novel Chiral Dihydroisoquinolinium Salts as Organocatalysts
Ali, K. Ben
, p. 638 - 646 (2021/06/02)
Abstract: Two new non-racemic chiral dihydroisoquinolinium salts with N-substituents bulkier than a methyl group have been synthesized from (1S,2R)-norephedrine. These salts were used to catalyze asymmetric epoxidation of a series of prochiral olefins. One of the two new catalysts provided higher enantioselectivities (up to 66% ee) than the reference salt containing an N-methyl substituent.
New biphenyl iminium salt catalysts for highly enantioselective asymmetric epoxidation: Role of additional substitution and dihedral angle
Bulman Page, Philip C.,Bartlett, Christopher J.,Chan, Yohan,Allin, Steven M.,McKenzie, Michael J.,Lacour, Jér?me,Jones, Garth A.
, p. 4220 - 4232 (2016/05/24)
New biaryl iminium salt catalysts for enantioselective alkene epoxidation containing additional substitution in the heterocyclic ring are reported. The effects upon conformation and enantioselectivity of this additional substitution, and the influence of dihedral angle in these systems, has been investigated using a synthetic approach supported by density functional theory. Enantioselectivities of up to 97% ee were observed.
Asymmetric epoxidation using iminium salt organocatalysts featuring dynamically controlled atropoisomerism
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
experimental part, p. 6128 - 6138 (2012/10/08)
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.
