6282-41-3Relevant academic research and scientific papers
Zirconocene-catalyzed direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio under solvent-free conditions
Tang, Zhi,Jiang, Qiutao,Peng, Lifen,Xu, Xinhua,Li, Jie,Qiu, Renhua,Au, Chak-Tong
supporting information, p. 5396 - 5402 (2017/11/22)
A highly efficient way for the direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio using a zirconocene complex (1, 1 mol%), a strong Lewis acid of good water tolerance, as a catalyst under solvent-free conditions has been developed. A wide range of acid and alcohol (esters) substrates undergo (trans)esterification to produce carboxylic ester motifs in moderate to good or excellent yields with good functional tolerance, such as that towards C-Br as well as CC and CC bonds. And complex 1 can be recycled six times without showing a significant decline in catalytic efficiency. It was demonstrated that cyclandelate, which is used to treat high blood pressure as well as heart and blood-vessel diseases, can be directly synthesized on a gram scale with 81% yield (6.70 g) using complex 1.
Toward a Large-Scale Approach to Milnacipran Analogues Using Diazo Compounds in Flow Chemistry
Müller, Simon T. R.,Murat, Aurélien,Hellier, Paul,Wirth, Thomas
, p. 495 - 502 (2016/03/04)
The safe use of diazo reagents for the preparation of a key structure in the synthesis of milnacipran analogues is described herein. Using continuous flow technology, the diazo reagent is synthesized, purified, dried, and subsequently used in semi-batch mode for an intramolecular cyclopropanation. Side products formed in the reaction are isolated and rationalized to optimize the process. Different separation techniques in flow are compared with regard to their ability to produce pure and dry diazo reagents. The studies yield a scalable process to a key intermediate in the syntheses of milnacipran and its possible substituted analogues.
Intramolecular 1,3-dipolar cycloaddition-mediated stereoselective synthesis of disubstituted cyclopentane: A simple model for the cyclopentane ring system of polycyclic oroidine alkaloids
Fukahori, Yusuke,Takayama, Yohei,Imaoka, Takuya,Iwamoto, Osamu,Nagasawa, Kazuo
, p. 244 - 250 (2013/02/23)
We present a diastereoselective synthesis of disubstituted cyclopentane 8 having a nitrogen-containing quaternary carbon center, which is found in axinellamine A (5) and related compounds. During this work, we found that the 1,3-dipolar cycloaddition product 24 immediately underwent intramolecular redox reaction at the newly formed morpholin-2-one moiety, thus affording disubstituted cyclopentane containing a tertiary amine (9) stereoselectively in good yield. The amine 9 was successfully converted into guanidine 31, which corresponds to 8, through iminium cation-enamine isomerization. Copyright
Scandium triflate catalyzed transesterification of carboxylic esters
Remme, Nicole,Koschek, Katharina,Schneider, Christoph
, p. 491 - 493 (2007/12/27)
The direct transesterification of carboxylic esters is efficiently catalyzed with Sc(OTf)3 (10 mol%) in boiling alcoholic solvent. Methyl, ethyl, isopropyl, and allyl esters were prepared from a broad range of different substrates in high yields. The application of microwave irradiation led to significantly reduced reaction times. Georg Thieme Verlag Stuttgart.
An efficient and convenient procedure for preparation of mandelates catalysed by TiO2/SO4/2- solid superacid
Jin,Ma,Li,Sun,Li
, p. 2051 - 2054 (2007/10/03)
An easy and efficient synthesis of mandelates in excellent yields from mandelic acid with alcohols catalysed by TiO2/SO42- solid superacid.
A general and simple synthesis of phenylglyoxylic esters via the oxidation of mandelic esters with ammonium chlorochromate adsorbed on alumina
Zhang, Gui-Sheng,Gong, Hui
, p. 3149 - 3153 (2007/10/03)
A general method for preparation of phenylglyoxylic esters by oxidation of mandelic esters with readily available ammonium chlorochromate adsorbed on alumina is described.
