66232-33-5Relevant academic research and scientific papers
Titanium salalen catalysts based on cis-1,2-diaminocyclohexane: Enantioselective epoxidation of terminal non-conjugated olefins with H 2O2
Berkessel, Albrecht,Guenther, Thomas,Wang, Qifang,Neudoerfl, Joerg-M.
, p. 8467 - 8471 (2013/09/02)
Terminal, non-conjugated olefins, such as 1-octene, are difficult to epoxidize asymmetrically. Ti salalen complexes based on cis-1,2- diaminocyclohexane catalyze this demanding reaction giving high yields and enantioselectivities (up to 95 % ee), with H2O2 as the oxidant. The X-ray structures of the μ-oxo and peroxo complexes shed light on the coordination behavior of this novel class of ligands.
The combination of mononuclear metallocene and phenoxyimine complexes to give trinuclear catalysts for the polymerization of ethylene
G?rl, Christian,Alt, Helmut G.
, p. 5727 - 5753 (2008/03/13)
Trinuclear complexes were synthesized by combination of metallocene and phenoxyimine zirconium complexes. After activation with methylalumoxane (MAO), these catalysts polymerize ethylene with moderate and good activities. Due to the presence of different catalytic centers, polyethylenes with broad or bimodal molecular weight distributions were obtained.
Radioiodine-Labeled N,N-Dimethyl-N'-(2-hydroxy-3-alkyl-5-iodobenzyl)-1,3-propanediamines for Brain Perfusion Imaging
Tramposch, Kenneth M.,Kung, Hank F.,Blau, Monte
, p. 121 - 125 (2007/10/02)
In developing new brain-imaging agents for single photon emission computed tomography (SPECT), we synthesized five radioiodinated N,N-dimethyl-N'-(2-hydroxy-3-alkyl-5-iodobenzyl)-1,3-propanediamines (12-16).The appropriate o-alkylphenol was formylated via a tin(IV) chloride catalyzed reaction.Iodination with iodine monochloride gave the required 3-alkyl-5-iodosalicylaldehyde, which was reductively aminated with 3-(dimethylamino)propylamine and sodium borohydride.The radioactive labeling (>95percent yield) can be achieved by a rapid aqueous exchange reaction in a serum vial at 100 deg C.Biodistribution in rats exhibited high initial brain uptake (0.9 to 1.8percent dose in brain at 2 min), and the brain activity remained about the same at 1 h for all the compounds.The best brain-imaging agent was N,N-dimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (12), which showed the highest uptake of 1.80 and 2.02percent dose in brain at 2 min and 1 h, respectively.The brain uptake increases when the specific activity of 125I-labeled 12 decreases.An imaging study of 12 in a monkey showed high initial brain uptake as well as high uptake in lungs and liver.The brain uptake persists for at least 1 h.Autoradiography of rat brain sections showed a regional distribution that reflects the cerebral perfusion pattern (high activity in gray matter and low activity in white matter).It is apparent that 12 is readily prepared and is potentially useful for brain perfusion imaging in conjunction with SPECT devices.
Selective Reactions between Phenols and Formaldehyde. A Novel Route to Salicylaldehydes
Casiraghi, Giovanni,Casnati, Giuseppe,Puglia, Giuseppe,Sartori, Giovanni,Terenghi, Giuliana
, p. 1862 - 1865 (2007/10/02)
Treatment of phenols (1) with 2 mol equiv. of paraformaldehyde in aprotic and poorly electron-donating solvents in the presence of selected metal halides coupled with suitable bases produces salicylaldehydes (3) in high yields.The route is highly selective for ortho-formylation and also specific towards monoformylation.The crucial role of added bases is emphasized.
