23165-29-9Relevant articles and documents
Highly Acidic Conjugate-Base-Stabilized Carboxylic Acids Catalyze Enantioselective oxa-Pictet–Spengler Reactions with Ketals
Zhu, Zhengbo,Odagi, Minami,Zhao, Chenfei,Abboud, Khalil A.,Kirm, Helmi Ulrika,Saame, Jaan,L?kov, M?rt,Leito, Ivo,Seidel, Daniel
supporting information, p. 2028 - 2032 (2019/12/24)
Acyclic ketone-derived oxocarbenium ions are involved as intermediates in numerous reactions that provide valuable products, however, they have thus far eluded efforts aimed at asymmetric catalysis. We report that a readily accessible chiral carboxylic acid catalyst exerts control over asymmetric cyclizations of acyclic ketone-derived trisubstituted oxocarbenium ions, thereby providing access to highly enantioenriched dihydropyran products containing a tetrasubstituted stereogenic center. The high acidity of the carboxylic acid catalyst, which exceeds that of the well-known chiral phosphoric acid catalyst TRIP, is largely derived from stabilization of the carboxylate conjugate base through intramolecular anion-binding to a thiourea site.
Isoselective Lactide Ring Opening Polymerisation using [2]Rotaxane Catalysts
Lim, Jason Y. C.,Yuntawattana, Nattawut,Beer, Paul D.,Williams, Charlotte K.
supporting information, p. 6007 - 6011 (2019/04/03)
Polylactide (PLA) is a fully biodegradable and recyclable plastic, produced from a bio-derived monomer: it is a circular economy plastic. Its properties depend upon its stereochemistry and isotactic PLA shows superior thermal-mechanical performances. Here, a new means to control tacticity by exploiting rotaxane conformational dynamism is described. Dynamic achiral [2]rotaxanes can show high isoselectivity (Pi=0.8, 298 K) without requiring any chiral additives and enchain by a chain end control mechanism. The organocatalytic dynamic stereoselectivity is likely applicable to other small-molecule and polymerization catalyses.
Design and discovery of thioether and nicotinamide containing sorafenib analogues as multikinase inhibitors targeting B-Raf, B-RafV600E and VEGFR-2
Sun, Shaofeng,He, Zuopeng,Huang, Mindong,Wang, Ningning,He, Zongzhong,Kong, Xiangkai,Yao, Jianwen
, p. 2381 - 2391 (2018/04/11)
New sorafenib derivatives containing thioether and nicotinamide moiety were designed and synthesized as B-Raf, B-RafV600E and VEGFR-2 multikinase inhibitors. Their in vitro enzymatic inhibitory activities against B-Raf, B-RafV600E and VEGFR-2 and their antiproliferative activities against HCT-116 and B16BL6 cell lines were evaluated and described. Most of the compounds showed potent activities against both cell lines and specific kinases. Compounds a1, b1 and c4, which exhibited the most potent inhibitory activities against B-Raf with IC50 of 21 nM, 27 nM and 17 nM, B-RafV600E with IC50 of 29 nM, 28 nM and 16 nM, VEGFR-2 with IC50 of 84 nM, 46 nM and 63 nM, respectively, and good antiproliferative activities, also demonstrated competitive antiangiogenic activities to sorafenib in in vitro HUVEC tube formation assay.