使用构象灵活的1,3 - 丁二烯桥连二膦（NUPHOS）的铂族配合物进行高效不对称路易斯酸催化。

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

作者信息

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

机构信息

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.

出版信息

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

DOI:10.1021/ol035409i

PMID:14535729

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, 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.

摘要

[结构：见正文] 构象灵活的1,3 - 丁二烯桥连二膦NUPHOS的钯和铂配合物在高温下可与(S)-联萘酚拆分，得到非对映纯的δ - [(NUPHOS)M[(S)-联萘酚]]（M = Pd，Pt）。通过用三氟甲磺酸质子化δ - [(NUPHOS)M[(S)-联萘酚]]生成的手性纯路易斯酸配合物δ - [(NUPHOS)M][OTf]₂，催化丙烯酰基 - N - 恶唑烷酮与环戊二烯之间的狄尔斯 - 阿尔德反应，对映体过量值高达96%。相应的对映纯二氯化物δ - [(NUPHOS)PtCl₂]与AgClO₄反应形成高效催化剂，具有良好的内型/外型选择性和高的内型对映选择性。