Evaluation of Fe and Ru Pincer-Type Complexes as Catalysts for the Racemization of Secondary Benzylic Alcohols

Christoph Bornschein; Karl P J Gustafson; Oscar Verho; Matthias Beller; Jan-E Bäckvall

doi:10.1002/chem.201601793

Evaluation of Fe and Ru Pincer-Type Complexes as Catalysts for the Racemization of Secondary Benzylic Alcohols

Chemistry. 2016 Aug 8;22(33):11583-6. doi: 10.1002/chem.201601793. Epub 2016 Jul 13.

Authors

Christoph Bornschein^{1

2}, Karl P J Gustafson¹, Oscar Verho¹, Matthias Beller², Jan-E Bäckvall³

Affiliations

¹ Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden.
² Leibniz-Institut für Katalyse e.V. an der Universität Rostock (LIKAT Rostock), Albert-Einstein-Strasse 29a, 18059, Rostock, Germany.
³ Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden. jeb@organ.su.se.

PMID: 27311070
DOI: 10.1002/chem.201601793

Abstract

Fe and Ru pincer-type catalysts are used for the racemization of benzylic alcohols. Racemization with the Fe catalyst was achieved within 30 minutes under mild reaction conditions, with a catalyst loading as low as 2 mol %. This reaction constitutes the first example of an iron-catalyzed racemization of an alcohol. The efficiency for racemization of the Fe catalyst and its Ru analogue was evaluated for a wide range of sec-benzylic alcohols. The commercially available Ru complex proved to be highly robust and even tolerated the presence of water in the reaction mixture.

Keywords: iron; pincer ligands; racemization; ruthenium; secondary alcohols.