6223-78-5Relevant articles and documents
A sterically expanded "Constrained Geometry Catalyst" for highly active olefin polymerization and copolymerization: An unyielding comonomer effect
Irwin, Levi J.,Reibenspies, Joseph H.,Miller, Stephen A.
, p. 16716 - 16717 (2004)
The 14 A octamethyloctahydrodibenzofluorene moiety has been incorporated into a sterically expanded constrained geometry catalyst, Me2Si(η1-C29H36)(η1-N-tBu)ZrCl2·OEt2 (1). The solid-state structure suggests that the activated olefin polymerization catalyst is quite spatially accessible, rationalizing its extraordinary reactivity toward α-olefins. 1/MAO (MAO = methylaluminoxane) can be more reactive toward α-olefins than toward ethylene and exhibit activities that are linearly and continuously proportional to 4-methyl-1-pentene or 1-octene concentration in their copolymerizations with ethylene. Copyright
Condon
, p. 761 (1956)
Synthetic method of retinoic acid derivative Am580
-
Paragraph 0032-0034, (2021/03/13)
The invention discloses a synthetic method of retinoic acid derivative Am580, which comprises: stirring a solution of 2, 5-dimethyl hexane-2, 5-diol in concentrated HCl for 30 min, introducing HCl gasinto the system, carrying out a reaction for 3 h, performing stirring until the system becomes a two-phase mixture, performing cooling to a room temperature, performing filtering to obtain a light pink solid, washing the solid with water, performing recrystallizing in methanol, and performing filtering to obtain an intermediate 3 which is a white solid; dissolving 2, 5-dichloro-2, 5-dimethylhexane in an organic solvent, adding AlCl3 into the solution according to a molar ratio of the 2, 5-dichloro-2, 5-dimethylhexane to the AlCl3 of 1: 0.1-1: 0.2, performing heating to 100-120 DEG C, performing stirring for 16 hours, quenching the reaction by using 3M HCl, performing extracting by using normal hexane, and performing distilling under reduced pressure to remove the solvent to obtain a colorless oily matter intermediate 4. The method has the beneficial effects that the yield of each step is relatively high, the post-treatment is simple, and the industrial production is easier; reaction conditions and a solvent system are optimized for the Friedel-Crafts reaction and the oxidation reaction, and industrial production is better facilitated.
The cubane paradigm in bioactive molecule discovery: Further scope, limitations and the cyclooctatetraene complement
Houston, Sevan D.,Fahrenhorst-Jones, Tyler,Xing, Hui,Chalmers, Benjamin A.,Sykes, Melissa L.,Stok, Jeanette E.,Farfan Soto, Clementina,Burns, Jed M.,Bernhardt, Paul V.,De Voss, James J.,Boyle, Glen M.,Smith, Maree T.,Tsanaktsidis, John,Savage, G. Paul,Avery, Vicky M.,Williams, Craig M.
supporting information, p. 6790 - 6798 (2019/07/22)
The cubane phenyl ring bioisostere paradigm was further explored in an extensive study covering a wide range of pharmaceutical and agrochemical templates, which included antibiotics (cefaclor, penicillin G) and antihistamine (diphenhydramine), a smooth muscle relaxant (alverine), an anaesthetic (ketamine), an agrochemical instecticide (triflumuron), an antiparasitic (benznidazole) and an anticancer agent (tamibarotene). This investigation highlights the scope and limitations of incorporating cubane into bioactive molecule discovery, both in terms of synthetic compatibility and physical property matching. Cubane maintained bioisosterism in the case of the Chagas disease antiparasitic benznidazole, although it was less active in the case of the anticancer agent (tamibarotenne). Application of the cyclooctatetraene (COT) (bio)motif complement was found to optimize benznidazole relative to the benzene parent, and augmented anticancer activity relative to the cubane analogue in the case of tamibarotene. Like all bioisosteres, scaffolds and biomotifs, however, there are limitations (e.g. synthetic implementation), and these have been specifically highlighted herein using failed examples. A summary of all templates prepared to date by our group that were biologically evaluated strongly supports the concept that cubane is a valuable tool in bioactive molecule discovery and COT is a viable complement.
An experimental and computational study on isomerically pure, soluble azaphthalocyanines and their complexes and boron azasubphthalocyanines of a varying number of aza units
Liebold, Martin,Sharikow, Eugen,Seikel, Elisabeth,Trombach, Lukas,Harms, Klaus,Zimcik, Petr,Novakova, Veronika,Tonner, Ralf,Sundermeyer, J?rg
supporting information, p. 6586 - 6599 (2018/09/25)
Herein, we present a series of isomerically pure, peripherally alkyl substituted, soluble and low aggregating azaphthalocyanines as well as their new, smaller hybrid homologues, azasubphthalocyanines. The focus lies on the effect of the systematically increasing number of aza building blocks [-N] replacing the non-peripheral [-CH] units and their influence on the physical and photophysical properties of these chromophores. The absolute and relative HOMO-LUMO energies of azaphthalocyanines were analyzed using UV-Vis and CV and compared to the density functional theory calculations (B3LYP, TD-DFT). The lowering of the HOMO level is revealed as the determining factor for the trend in the adsorption energies by electronic structure analysis. Crystals of substituted subphthalocyanines, N2-Pc?H2 and N4-[Pc?Zn·H2O], were obtained out of DCM. For the synthesis of the valuable tetramethyltetralin phthalocyanine building block a new highly efficient synthesis involving a nearly quantitative CoII catalyzed aerobic autoxidation step is introduced replacing inefficient KMnO4/pyridine as the oxidant.