Tetrahedron: Asymmetry

Development of a novel chiral spiro ligand bearing oxazoline

T Kato, K Marubayashi, S Takizawa, H Sasai

Index: Kato, Takahiro; Marubayashi, Kazuyoshi; Takizawa, Shinobu; Sasai, Hiroaki Tetrahedron Asymmetry, 2004 , vol. 15, # 23 p. 3693 - 3697

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Citation Number: 36

Abstract

The synthesis of bis (oxazoline) ligand 1 bearing a spiro skeleton is achieved via double ring-closing metathesis (RCM) of tetraene 2 and subsequent oxazoline ring formation using N-bromosuccinimide (NBS). The Cu-spiro bis (oxazoline) complexes prepared from 1 and Cu (OTf) 2 or Cu (OAc) 2 act efficiently as chiral catalysts for promoting carbonyl-ene reactions or Henry reactions with good enantiocontrol.