Metal-Free, Mild, Nonepimerizing, Chemo- and Enantio- or Diastereoselective N-Alkylation of Amines by Alcohols via Oxidation/Imine–Iminium Formation/Reductive Amination: A Pragmatic Synthesis of Octahydropyrazinopyridoindoles and Higher Ring Analogues
作者:Imran A. Khan、Anil K. Saxena
DOI:10.1021/jo4012249
日期:2013.12.6
A mild step and atom-economical nonepimerizing chemo- and enantioselective N-alkylating procedure has been developed via oxidation/imine–iminium formation/reduction cascade using TEMPO–BAIB–HEH–Brønsted acid catalysis in DMPU as solvent and a stoichiometric amount of amine. The optimized conditions were further extended for the nonenzymatic kinetic resolution of the chiral amine thus formed under nonenzymatic
The invention relates to a process for the production of polyethylene by gas phase polymerisation of ethylene in the presence of a supported chromium oxide based catalyst which is modified with an amino alcohol wherein the molar ratio of amino alcohol:chromium ranges between 0.5:1 and 1.5:1 wherein the support is silica having a surface area (SA) between 250 m2/g and 400 m2/g and a pore volume (PV) between 1.1 cm3/g and less than 2.0 cm3/g.