Synthesis 2004(15): 2567-2573  
DOI: 10.1055/s-2004-831207
PAPER
© Georg Thieme Verlag Stuttgart · New York

Titanocene-Catalyzed Reductive Epoxide Opening: The Quest for Novel Hydrogen Atom Donors

Andreas Gansäuer*, Andriy Barchuk, Doris Fielenbach
Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität, Gerhard Domagk Str.1, 53121 Bonn, Germany
Fax: +49(228)734760; e-Mail: andreas@gansaeuer.de;
Further Information

Publication History

Received 5 May 2004
Publication Date:
02 September 2004 (online)

Abstract

Novel hydrogen atom donors for the reductive titanocene-catalyzed epoxide opening are presented. While the potentially attractive cyclopentadienes gave only moderate yields of the desired alcohols, substituted, nontoxic, and commercially available 1,4-cyclohexadienes, e.g. γ-terpinene, in combination with more elaborate catalysts gave better or similar results than the much more expensive and carcinogenic 1,4-cyclohexadiene. In the practically important reactions of Sharpless epoxides and their derivatives excellent levels of regioselectivity for the epoxide opening could be obtained. The toxic and unpleasant to handle tert-butyl thiol could be replaced while increasing the yields of the desired products.