Highly efficient asymmetric Lewis acid catalysis with platinum group complexes of conformationally flexible 1,3-butadiene-bridged diphosphines, NUPHOS

Simon Doherty; Colin R Newman; Rakesh K Rath; He-Kuan Luo; Mark Nieuwenhuyzen; Julian G Knight

doi:10.1021/ol035409i

Highly efficient asymmetric Lewis acid catalysis with platinum group complexes of conformationally flexible 1,3-butadiene-bridged diphosphines, NUPHOS

Org Lett. 2003 Oct 16;5(21):3863-6. doi: 10.1021/ol035409i.

Authors

Simon Doherty¹, Colin R Newman, Rakesh K Rath, He-Kuan Luo, Mark Nieuwenhuyzen, Julian G Knight

Affiliation

¹ Centre for the Theory and Applications of Catalysis, School of Chemistry, The Queen's University of Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK. [email protected]

PMID: 14535729
DOI: 10.1021/ol035409i

Abstract

[structure: see text] Palladium and platinum complexes of conformationally flexible 1,3-butadiene-bridged diphosphines NUPHOS can be resolved with (S)-BINOL at elevated temperatures to afford diastereopure delta-[(NUPHOS)M[(S)-BINOL]] (M = Pd, Pt). The homochiral Lewis acid complexes delta-[(NUPHOS)M][OTf](2), generated by protonation of delta-[(NUPHOS)M[(S)-BINOL]] with trifluoromethanesulfonic acid, catalyze the Diels-Alder reaction between acryloyl-N-oxazolidinones and cyclopentadiene to give ee values up to 96%. The corresponding enantiopure dichlorides delta-[(NUPHOS)PtCl(2)] react with AgClO(4) to form highly efficient catalysts that give good endo/exo selectivities and high endo enantioselectivity.