Universität zu Köln

Wartmann, Christina ORCID: 0000-0002-3275-8284, Neudörfl, Jörg.‐M. ORCID: 0000-0002-2918-0565 and Berkessel, Albrecht ORCID: 0000-0003-0470-7428 (2025). Titanium cis ‐DACH Salan Catalyst for the Efficient Epoxidation of Nonactivated Olefins with Hydrogen Peroxide‐Terminal‐Selective Epoxidation of Multiply Unsaturated Terpenes. Dedicated to Professor Günter Helmchen on the occasion of his 85th birthday. Chemistry – A European Journal, 31 (39). pp. 1-6. Wiley. ISSN 0947-6539

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Abstract

[Artikel-Nr.: e202501688] We report a new generation of highly active and readily available homogeneous titanium catalysts for the epoxidation of nonactivated olefins with aqueous hydrogen peroxide. Key feature is the introduction of pentafluorophenyl substituents into a salan ligand derived from cis ‐1,2‐diaminocyclohexane ( cis ‐DACH). Our novel salan ligand is accessible in one single step by reductive alkylation of cis ‐DACH with 3‐(pentafluorophenyl)salicylic aldehyde. In situ complexation with Ti(O i Pr) 4 of the cis ‐DACH salan provides the titanium catalyst, which, in the presence of aqueous hydrogen peroxide, smoothly epoxidizes a broad spectrum of olefins with up to 95% yield at a catalyst loading of 0.5 mol‐% only. The achiral cis ‐DACH salan catalyst showed syn ‐selectivity (4.7:1) in the epoxidation of a chiral, racemic terminal allylic alcohol. This catalyst furthermore allows the regioselective (up to 49:1) epoxidation of the terminal double bond in multiply unsaturated terpenes such as myrcene, ( S )‐citronellene, and ( R )‐linalool. For the latter two substrates, syn/anti ‐selectivity of up to 9:1 was observed. Augmented syn/anti selectivity (up to 50:1 syn or 25:1 anti ) can be induced in the epoxidation of the chiral substrates ( S )‐citronellene and ( R )‐linalool when the “matched” enantiomer of the chiral “Berkessel salalen ligand” is employed.

Item Type:	Article
Creators:	Creators Email ORCID ORCID Put Code Wartmann, Christina UNSPECIFIED https://orcid.org/0000-0002-3275-8284 UNSPECIFIED Neudörfl, Jörg.‐M. UNSPECIFIED https://orcid.org/0000-0002-2918-0565 UNSPECIFIED Berkessel, Albrecht UNSPECIFIED https://orcid.org/0000-0003-0470-7428 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-803050
Identification Number:	10.1002/chem.202501688
Journal or Publication Title:	Chemistry – A European Journal
Volume:	31
Number:	39
Page Range:	pp. 1-6
Number of Pages:	6
Date:	11 July 2025
Publisher:	Wiley
ISSN:	0947-6539
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Organic Chemistry
Subjects:	Chemistry and allied sciences
['eprint_fieldname_oa_funders' not defined]:	Publikationsfonds UzK
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/80305