Using stereocartography for predicting efficacy of stereoinduction by chiral catalysts.

A computational method called stereocartography is used to examine regions around chiral catalysts that are most stereoinducing during Diels-Alder reactions. Geometries and atomic charges of catalysts are first generated quantum mechanically. The transition state of the reaction being catalyzed is then computed quantum mechanically and those enantiomeric transition states are used as probes to determine where around the catalyst stereoinduction is optimal. A description of how to treat catalysts with multiple conformations is given. In this article seven catalysts containing a variety of ligand motifs and metals were evaluated. The hypothesis that the region of maximum stereoinduction must be spatially coincident with the site of chemistry for a catalyst to be efficient is upheld.

[1]  P. White,et al.  Electron-poor benzonitriles as labile, stabilizing ligands in asymmetric catalysis. , 2002, Organic letters.

[2]  P. Norrby,et al.  Chromium-salen-mediated alkene epoxidation: a theoretical and experimental study indicates the importance of spin-surface crossing and the presence of a discrete intermediate. , 2002, Chemistry.

[3]  Meeta Pradhan,et al.  Computational studies of chiral catalysts: a comparative molecular field analysis of an asymmetric Diels-Alder reaction with catalysts containing bisoxazoline or phosphinooxazoline ligands. , 2003, The Journal of organic chemistry.

[4]  S. Collins,et al.  Asymmetric induction in the Diels-Alder reaction using chiral metallocene catalysts , 1993 .

[5]  S. L. Dixon,et al.  Quantum mechanical models correlating structure with selectivity: predicting the enantioselectivity of beta-amino alcohol catalysts in aldehyde alkylation. , 2003, Journal of the American Chemical Society.

[6]  Yuichiro Suzuki,et al.  A novel and efficient chiral palladium–phosphinooxazolidine catalyst for the enantioselective Diels–Alder reactionElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b2/b201625g/ , 2002 .

[7]  Kazuhiro Watanabe,et al.  New chiral sulfoxide ligands in catalytic asymmetric Diels–Alder reactions: double acceleration by the chiralities of the sulfoxides and oxazolines , 2001 .

[8]  M. Kozlowski,et al.  Understanding Stereoinduction in Catalysis via Computer: New Tools for Asymmetric Synthesis , 2003 .

[9]  Eric N. Jacobsen,et al.  Comprehensive asymmetric catalysis , 1999 .

[10]  Yuichiro Suzuki,et al.  Chiral phosphinooxathiane ligands for catalytic asymmetric Diels-Alder reaction. , 2002, The Journal of organic chemistry.

[11]  G. Bernardinelli,et al.  Chiral Bidentate (Phosphinophenyl)benzoxazine Ligands in Asymmetric Catalysis , 2001 .

[12]  G. Chang,et al.  Macromodel—an integrated software system for modeling organic and bioorganic molecules using molecular mechanics , 1990 .