Conformational Preferences and Enantiodiscrimination of Phosphino-4-(1-hydroxyalkyl)oxazoline−Metal−Olefin Complexes Resulting from an OH−Metal Hydrogen Bond
- 1 November 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 70 (24) , 9882-9891
- https://doi.org/10.1021/jo051610q
Abstract
[reaction: see text] Phosphinooxazolines carrying (1-hydroxy-1-phenyl)methyl and (1-methoxy-1-phenyl)methyl substituents in the 4 position of the oxazoline ring exhibit contrasting behavior in Pd- and Ir-catalyzed allylic alkylations. Whereas catalysts with the methoxy-containing ligand generally provide products with high ee's, use of catalysts prepared from the hydroxy-containing ligand results in products with low ee's or even racemates. DFT calculations suggest the presence of a hydrogen bond with Pd(0) as the proton acceptor in the hydroxy-containing olefin-Pd(0) complexes, which induces a conformational change in the ligand, leading to different stereoselectivity.Keywords
This publication has 30 references indexed in Scilit:
- Asymmetric Iridium(I)-Catalyzed Allylic Alkylation of Monosubstituted Allylic Substrates with Phosphinooxazolines as Ligands. Isolation, Characterization, and Reactivity of Chiral (Allyl)iridium(III) ComplexesOrganometallics, 2004
- Kinetic Resolution of Amines: A Highly Enantioselective and Chemoselective Acetylating Agent with a Unique Solvent‐Induced Reversal of StereoselectivityAngewandte Chemie International Edition in English, 2004
- Different Lanthanide Ions and the Pybox Substituents Induce the Reverse of the Sense of Induction in the Enantioselective Diels−Alder Reaction between Acryloyloxazolidinone and CyclopentadieneThe Journal of Organic Chemistry, 2003
- X-ray crystallographic and NMR spectroscopical characterization of intermediates in the Pd-catalyzed allylic substitution reaction with 4-substituted phosphinooxazolines. Correlation between intermediate structure and product configurationInorganica Chimica Acta, 2002
- Versatile Chiral Bidentate Ligands Derived from α-Amino Acids: Synthetic Applications and Mechanistic Considerations in the Palladium-Mediated Asymmetric Allylic SubstitutionsThe Journal of Organic Chemistry, 2000
- (Hydroxyalkyl)pyridinooxazolines in Palladium-Catalyzed Allylic Substitutions. Conformational Preferences of the LigandOrganometallics, 1999
- Reactivity Indices in Density Functional Theory: A New Evaluation of the Condensed Fukui Function by Numerical IntegrationThe Journal of Physical Chemistry A, 1998
- Palladium‐Catalyzed Allylic Alkylation with Phosphinoaryldihydrooxazole Ligands: First Evidence and NMR Spectroscopic Structure Determination of a Primary Olefin–Pd0 ComplexAngewandte Chemie International Edition in English, 1997
- First-Principles Investigation of Enantioselective Catalysis: Asymmetric Allylic Amination with Pd Complexes Bearing P,N-LigandsOrganometallics, 1996
- New Pt …︁ H-N bonds characterized by 15N‐filtered and 2D NOESY 1H NMR spectroscopyMagnetic Resonance in Chemistry, 1992