95043-56-4Relevant articles and documents
Titanium cis-1,2-Diaminocyclohexane Salalen Catalysts of Outstanding Activity and Enantioselectivity for the Asymmetric Epoxidation of Nonconjugated Terminal Olefins with Hydrogen Peroxide
Lansing, Markus,Engler, Hauke,Leuther, Tobias M.,Neud?rfl, J?rg-M.,Berkessel, Albrecht
, p. 3706 - 3709 (2016/12/24)
We 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.
Synthesis of a putative advanced intermediate en route to elisabethin A
Steiner, Sebastian,G?rtner, Peter,Enev, Valentin S.
, p. 4536 - 4542 (2016/07/07)
The first generation synthesis of an advanced intermediate en route to elisabethin A is described.
Shell cross-linked micelle-based nanoreactors for the substrate-selective hydrolytic kinetic resolution of epoxides
Liu, Yu,Wang, Yu,Wang, Yufeng,Lu, Jie,Pinon, Victor,Weck, Marcus
supporting information; experimental part, p. 14260 - 14263 (2011/11/05)
Shell cross-linked micelles (SCMs) containing Co(III)-salen cores were prepared from amphiphilic poly(2-oxazoline) triblock copolymers. The catalytic activity of these nanoreactors for the hydrolytic kinetic resolution of various terminal epoxides was investigated. The SCM catalysts showed high catalytic efficiency and, more significantly, substrate selectivity based on the hydrophobic nature of the epoxide. Moreover, because of the nanoscale particle size and the high stability, the catalyst could be recovered easily by ultrafiltration and reused with high activity for eight cycles.