ChemInform Abstract: Titanium Salalen Catalysts Based on cis‐1,2‐Diaminocyclohexane: Enantioselective Epoxidation of Terminal Non‐Conjugated Olefins with H₂O₂.

Abstract

Titanium Salalen Catalysts Based on cis-1,2-Diaminocyclohexane: Enantioselective Epoxidation of Terminal Non-Conjugated Olefins with H2O2. -This describes the first synthesis of various salalen ligands based on cis-diaminocyclohexane, the characterization of their Ti complexes, and their application in Ti-catalyzed asymmetric epoxidations. These new ligands are particularly useful for the asymmetric epoxidation of non-conjugated terminal olefins, which are a difficult substrate class for this type of reaction. -(BERKESSEL*, A.; GUENTHER, T.; WANG, Q.; NEUDOERFL, J.-M.; Angew. Chem., Int. Ed. 52 (2013) 32, 8467-8471, http://dx.

Kinetic resolution of indolines by asymmetric hydroxylamine formation

“…ESI mass-spectrometry analysis of the mixture of di-μ-oxo titanium(salalen) C6 and 30% aqueous H 2 O 2 after 30 min showed the peak of 1797.6, which is equal to [M C6 + O + H] + , implying the formation of a μ-oxo-μ-peroxo species S (Fig. 7a ) 56 . However, a lower intensity of this peak was observed for mixing C6 and H 2 O 2 after 15 min, implying that the formation of S might be a slow process.…”