1007346-01-1Relevant academic research and scientific papers
Asymmetric anion-π catalysis of iminium/nitroaldol cascades to form cyclohexane rings with five stereogenic centers directly on π-acidic surfaces
Liu, Le,Cotelle, Yoann,Avestro, Alyssa-Jennifer,Sakai, Naomi,Matile, Stefan
, p. 7876 - 7879 (2016)
Anion-π interactions have been introduced to catalysis only recently, and evidence for their significance is so far limited to one classical model reaction in enolate and enamine chemistry. In this report, asymmetric anion-π catalysis is achieved for the first time for a more demanding cascade process. The selected example affords six-membered carbocycles with five stereogenic centers in a single step from achiral and acyclic substrates. Rates, yields, turnover, diastereo- and enantioselectivity are comparable with conventional catalysts. Rates and stereoselectivity increase with the π-acidity of the new anion-π catalysts. Further support for operational anion-π interactions in catalysis is obtained from inhibition with nitrate. As part of the stereogenic cascade reaction, iminium chemistry and conjugate additions are added to the emerging repertoire of asymmetric anion-π catalysis.
How to make five contiguous stereocenters in one reaction: Asymmetric organocatalytic synthesis of pentasubstituted cyclohexanes
Reyes, Efraim,Jiang, Hao,Milelli, Andrea,Elsner, Petteri,Hazell, Rita G.,Jorgensen, Karl Anker
, p. 9202 - 9205 (2008/12/22)
(Chemical Equation Presented) Give me five! An organocatalyzed two-component domino reaction has been developed in which two new C-C bonds and five stereocenters are created in a one-pot fashion (see scheme; DABCO = 1,4-diazabicyclo[2.2.2]octane, TMS = trimethylsilyl). The striking features of this transformation are the high preference for one diastereomer (out of 32 possible isomers) and enantioselectivities of up to 94 %.
