2-Phenyliminomethylphenols, 2-phenylaminomethylphenols and their copper(II) complexes
作者:H.J. Harries、B.F. Orford、J. Burgess
DOI:10.1016/s0020-1693(00)88934-3
日期:1983.1
2-phenyliminomethylphenols (I) and 2-phenylaminomethylphenols (II) are described. Acid dissociation constants, determined potentiometrically, for the amines (II) are related to substituent constants; values are not obtained for Schiff bases(I) due to their hydrolysis. IR spectra of the amines (II) indicate chelate ring formation via OH⋯N hydrogen bonding. NMR spectra for Schiff bases (I) are consistent
chemodivergent reaction between stabilised sulfur ylides and salicylaldehydes, leading to the (suprising) formation of 2H-chromenes or dihydrobenzofurans products. Particular attention was set on the unusual mechanisms involved. Two unique reaction routes including two ylide units in the reactions are proposed. These pathways were validated by performing a selectivity switch in some cases, enabled
Catalytic Asymmetric Inverse-Electron-Demand (IED) [4+2] Cycloaddition of Salicylaldimines: Preparation of Optically Active 4-Aminobenzopyran Derivatives
The catalyticasymmetricinverse-electron-demand (IED) [4+2] cycloaddition of various salicylaldehyde-derived N-arylimines with electron-rich alkenes in the presence of chiral BINOL-derived phosphoric acid catalysts has been studied with the aim of obtaining opticallyactive4-aminobenzopyranderivatives. Dienophiles such as 2,3-dihydro-2H-furan, benzyl N-vinylcarbamate and 2-vinylindole have been
been developed and applied to multicomponent polymerization and controlled radical polymerization for the construction of random and block copolymers. This chemistry features mild reaction conditions, high yield, simple isolation, and water as the only byproduct. With the advantages of the distinct nucleophilicity of thiol and hydroxyl groups, the chemistry could be used for stepwise labeling and modifications
Methyltrioxorhenium-catalyzed oxidation of pseudocumene for vitamin E synthesis: A study of solvent and ligand effects
作者:Mónica Carril、Philipp Altmann、Markus Drees、Werner Bonrath、Thomas Netscher、Jan Schütz、Fritz E. Kühn
DOI:10.1016/j.jcat.2011.07.003
日期:2011.10
VitaminE is an essential food component of major economical relevance with important antioxidant properties and biological activity. The oxidation of pseudocumene to trimethyl-1,4-benzoquinone would be a key transformation in an alternative industrial production of α-tocopherol that is important for the antioxidant activity of vitaminE. The methyltrioxorhenium (MTO)-catalyzed oxidation of pseudocumene