Diels−Alder Cycloaddition Strategy for Kinetic Resolution of Chiral Pyrazolidinones
作者:Mukund P. Sibi、Keisuke Kawashima、Levi M. Stanley
DOI:10.1021/ol901504p
日期:2009.9.3
A rare example of the application of a catalytic, enantioselective Diels−Aldercycloaddition to affect a kinetic resolution has been developed. Chiral pyrazolidinones are resolved with high selectivity through a process that utilizes a relay of stereochemical information from a permanent chiral center to a fluxional chiral center to enhance the inherent selectivity of the chiral Lewis acid catalyst
Kinetic Resolution of Azomethine Imines by Brønsted Acid Catalyzed Enantioselective Reduction
作者:Amanda Bongers、Patrick J. Moon、André M. Beauchemin
DOI:10.1002/anie.201507548
日期:2015.12.14
Azomethine imines are valuable substrates in asymmetric catalysis, and can be precursors to β‐amino carbonyl compounds and complex hydrazines. However, their utility is limited because complex and enantioenriched azomethine imines are often unavailable. Reported herein is a kinetic resolution of N,N′‐cyclic azomethine imines by enantioselectivereduction (s=13–43). This resolution was accomplished
Structural effects in pyrazolidinone-mediated organocatalytic Diels–Alder reactions
作者:Eoin Gould、Tomas Lebl、Alexandra M.Z. Slawin、Mark Reid、Andrew D. Smith
DOI:10.1016/j.tet.2010.09.021
日期:2010.11
promoted Diels–Alderreactions evaluated. Systematic variation of the C(5)- and N(2)-substituents indicates that the incorporation of an electron withdrawing substitutent at N(2) and either a Ph or CF3 substitution at C(5) results in optimal catalytic activity. The diastereoisomeric resolution of a model C(5)-Ph substituted pyrazolidinone and its ability to impart modest levels of asymmetric induction