933-48-2Relevant articles and documents
Heterogeneous Hydroxyl-Directed Hydrogenation: Control of Diastereoselectivity through Bimetallic Surface Composition
Shumski, Alexander J.,Swann, William A.,Escorcia, Nicole J.,Li, Christina W.
, p. 6128 - 6134 (2021/05/29)
Directed hydrogenation, in which product selectivity is dictated by the binding of an ancillary directing group on the substrate to the catalyst, is typically catalyzed by homogeneous Rh and Ir complexes. No heterogeneous catalyst has been able to achieve equivalently high directivity due to a lack of control over substrate binding orientation at the catalyst surface. In this work, we demonstrate that Pd-Cu bimetallic nanoparticles with both Pd and Cu atoms distributed across the surface are capable of high conversion and diastereoselectivity in the hydroxyl-directed hydrogenation reaction of terpinen-4-ol. We postulate that the OH directing group adsorbs to the more oxophilic Cu atom while the olefin and hydrogen bind to adjacent Pd atoms, thus enabling selective delivery of hydrogen to the olefin from the same face as the directing group with a 16:1 diastereomeric ratio.
Synthesis method of cyclospasmol drug intermediate cis-3,3,5-trimethylcyclohexanol
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Paragraph 0019; 0026-0030, (2017/07/21)
The invention discloses a synthesis method of the cyclospasmol drug intermediate cis-3,3,5-trimethylcyclohexanol. The method includes the steps that 1,5,5-trimethyl cyclohexene-3-ketone is added into a 2-amino-5-chlorobenzoic acid solution, the temperature is decreased, and stirring is carried out; lithium powder is slowly added, a reaction is carried out after lithium powder is added, then, the temperature is increased, and the reaction continues; vacuum concentration is carried out, concentrated liquor is added into a potassium bromide solution, then, an oxalic acid solution is added, finally, a dimethylamine solution is subjected to extraction, washing, dehydrant dehydration, reduced pressure distillation and recrystallization, and the crystal cis-3,3,5-trimethylcyclohexanol is obtained. Compared with a traditional synthesis method, by means of the method, the reaction speed is greatly increased; a new synthesis route is provided, and a good foundation is laid for further increasing the reaction yield.
Selective reduction of organic compounds with Al- trifluoromethanesulfonyldiisobutylalane. Comparison of its reactivity with Al-methanesulfonyldiisobutylalane
Cha, Jin Soon
experimental part, p. 219 - 224 (2011/11/06)
The new MPV type reagent, Al-trifluoromethanesulfonyldiisobutylalane (DIBAO3SCF3), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined, and compared its reactivity with that of Al-methanesulfonyldiisobutylalane (DIBAO3SCH 3) in order to understand the fluorine-substituent effect on its reactivity. In general, the reactivity of DIBAO3SCF3 appears to be much higher than that of DIBAO3SCH3, apparently due to the acidity increase by the electron-withdrawing fluorine-substituent. The reagent reduced aldehydes and ketones readily, but showed a perfect selectivity in the reduction of α,β-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagent achieved the regioselective cleavage of phenyl-or/and alkyl-substituted epoxides to the less substituted alcohols in a perfect regioselectivity. Moreover, the reagent also showed an high stereoselectivity in the reduction of substituted cycloalkanones to produce the thermodynamically more stable alcohol epimers exclusively.
