Lansing, Markus;
Engler, Hauke;
Leuther, Tobias M.;
Neudörfl, Jörg‐M.;
Berkessel, Albrecht
Titanium cis‐1,2‐Diaminocyclohexane Salalen Catalysts of Outstanding Activity and Enantioselectivity for the Asymmetric Epoxidation of Nonconjugated Terminal Olefins with Hydrogen Peroxide
Sie können Bookmarks mittels Listen verwalten, loggen Sie sich dafür bitte in Ihr SLUB Benutzerkonto ein.
Medientyp:
E-Artikel
Titel:
Titanium cis‐1,2‐Diaminocyclohexane Salalen Catalysts of Outstanding Activity and Enantioselectivity for the Asymmetric Epoxidation of Nonconjugated Terminal Olefins with Hydrogen Peroxide
Beteiligte:
Lansing, Markus;
Engler, Hauke;
Leuther, Tobias M.;
Neudörfl, Jörg‐M.;
Berkessel, Albrecht
Erschienen:
Wiley, 2016
Erschienen in:
ChemCatChem, 8 (2016) 24, Seite 3706-3709
Sprache:
Englisch
DOI:
10.1002/cctc.201601154
ISSN:
1867-3880;
1867-3899
Entstehung:
Anmerkungen:
Beschreibung:
AbstractWe report a new and readily accessible class of titanium salalen complexes derived from cis‐1,2‐diaminocyclohexane (cis‐DACH) and fluorinated salicylic aldehyde derivatives. With aqueous hydrogen peroxide as the oxidant, these complexes catalyze the epoxidation of terminal, nonconjugated olefins in high yields with high enantioselectivities. We furthermore discovered that the addition of certain acidic or basic co‐catalysts significantly accelerated the epoxidation. For example, in the presence of 1 mol % Ti catalyst and 1 mol % pentafluorobenzoic acid, 1‐octene epoxidation (95 % ee) was completed at room temperature within 8 h. The catalytic process was compatible with many functional groups (e.g., ethers, esters, halides, nitriles, and nitro groups), whereas free hydroxy groups appeared to slow down the reaction to some extent. Catalyst recycling was possible.