898562-69-1Relevant academic research and scientific papers
Isothiourea-Catalyzed Acylative Kinetic Resolution of Tertiary α-Hydroxy Esters
Greenhalgh, Mark D.,Laina-Martín, Víctor,Neyyappadath, Rifahath M.,Qu, Shen,Smith, Andrew D.,Smith, Samuel M.
, p. 16572 - 16578 (2020/09/09)
A highly enantioselective isothiourea-catalyzed acylative kinetic resolution (KR) of acyclic tertiary alcohols has been developed. Selectivity factors of up to 200 were achieved for the KR of tertiary alcohols bearing an adjacent ester substituent, with both reaction conversion and enantioselectivity found to be sensitive to the steric and electronic environment at the stereogenic tertiary carbinol centre. For more sterically congested alcohols, the use of a recently-developed isoselenourea catalyst was optimal, with equivalent enantioselectivity but higher conversion achieved in comparison to the isothiourea HyperBTM. Diastereomeric acylation transition state models are proposed to rationalize the origins of enantiodiscrimination in this process. This KR procedure was also translated to a continuous-flow process using a polymer-supported variant of the catalyst.
Reformatsky and Blaise reactions in flow as a tool for drug discovery. One pot diversity oriented synthesis of valuable intermediates and heterocycles
Huck,Berton,De La Hoz,Díaz-Ortiz,Alcázar
supporting information, p. 1420 - 1424 (2017/05/12)
The application of Reformatsky and Blaise reactions for the preparation of a diverse set of valuable intermediates and heterocycles in a one-pot protocol is described. To achieve this goal, a greener activation protocol for zinc in flow conditions has been developed to introduce this metal efficiently into α-bromoacetates. The organozinc compounds were added to a diverse set of ketones and nitriles to obtain a wide range of functional groups and heterocyclic systems.
Synthesis and antitumour activity of β-hydroxyisovalerylshikonin analogues
Rao, Zhen,Liu, Xin,Zhou, Wen,Yi, Jing,Li, Shao-Shun
experimental part, p. 3934 - 3941 (2011/11/12)
A series of novel β-hydroxyisovalerylshikonin analogues bearing oxygen-containing substituents at the side-chain hydroxyl of shikonin were designed and synthesized. The cytotoxicities of these compounds were evaluated in vitro against multi-drug resistant (MDR) cell lines DU-145 and HeLa. Most compounds exhibited significant inhibitory activity on both cell lines. The structure-activity relationship showed the analogues with ether substituents displayed the most potent antitumour activity and selective cytotoxicity towards DU-145. Among the compounds with ether substituents, increasing the steric hindrance in the carbon bearing β-hydroxyl or replace the β-hydroxyl with acetoxy or methoxy would lead to the decline of cytotoxicity.
Iron-catalyzed oxidative addition of alkoxycarbonyl radicals to alkenes with carbazates and air
Taniguchi, Tsuyoshi,Sugiura, Yuki,Zaimoku, Hisaaki,Ishibashi, Hiroyuki
supporting information; experimental part, p. 10154 - 10157 (2011/02/24)
Clean and simple: Alkoxycarbonyl radicals generated from carbazates by iron catalysis in air underwent addition to a variety of alkenes to give the corresponding β-hydroxyesters (see scheme). The simple experimental procedure for this transformation has the added advantage that the reagents are environmentally friendly. R1,R2=alkyl, alkynyl, aryl, CO2Et; [Fe(Pc)]=iron phthalocyanine. Copyright
