Covalently anchored chlorosulfonyl-calix[4]arene onto silica gel as an efficient and reusable heterogeneous system for reduction of ketones using NaBH4
ne-bonded silicagel (CSC[4]A-SG) as a novel heterogeneous catalyst was illustrated by efficient reduction of various ketones to their corresponding alcohols. To illustrate the promoting effect of the catalyst in the reaction, two more series of parallel experiments were also carried out using bare silicagel and no catalyst. The study suggests that this newly synthesized solid catalyst has high binding
carboxy group further increased activity and duration of action in the rat. The most active racemic compound, 6al (R4 = isobutyl; R = ethoxy), turned out to be 12 times more active than the sulfonylurea (SU) glibenclamide (1). Activity was found to reside predominantly in the (S)-enantiomers. Compared with the SUs 1 and 2 (glimepiride), the most active enantiomer, (S)-6al (AG-EE 623 ZW; repaglinide;
研究了两个系列的降血糖苯甲酸衍生物(5、6)的构效关系。当2-甲氧基被亚烷基亚氨基残基取代时,系列5由美格替宁(3)产生。用顺式3、5-二甲基哌啶子基(5h)和八亚甲基亚氨基(5l)残基观察到最大活性。当将2-甲氧基,5-氟和α-甲基残基替换为2-哌啶子基,5-氢和较大的α-烷基残基时,具有反向酰胺基功能的meglitinide类似物4产生6系列, 分别。羧基邻位的烷氧基残基进一步增加了大鼠的活性和作用时间。最具活性的外消旋化合物6al(R4 =异丁基; R =乙氧基)的活性比磺酰脲(SU)格列本脲(1)高12倍。发现活性主要存在于(S)-对映异构体中。与SUs 1和2(格列美脲)相比,活性最高的对映异构体(S)-6al(AG-EE 623 ZW;瑞格列奈; ED50 = 10 micro / kg po)活性高25和18倍。瑞格列奈对2型糖尿病患者是一种有用的治疗药物。FDA和EMEA最
Insertion of arynes into carbon–halogen σ-bonds: regioselective acylation of aromatic rings
Arynes were found to insert into carbonâhalogen Ï-bonds of various acid halides, enabling acyl and halogen moieties to be introduced simultaneously into adjacent positions of aromatic rings.
氮烯能够插入各种酰卤中的碳-卤素σ键,从而使得酰基和卤素基团同时引入到芳香环的相邻位置。
Copper-dipyridylphosphine-catalyzed hydrosilylation: enantioselective synthesis of aryl- and heteroarylcycloalkyl alcohols
作者:Shan-Bin Qi、Min Li、Shijun Li、Ji-Ning Zhou、Jun-Wen Wu、Feng Yu、Xi-Chang Zhang、Albert S. C. Chan、Jing Wu
DOI:10.1039/c2ob27040d
日期:——
hydrosilylation of a vast array of aryl cycloalkyl ketones with different ring sizes was studied systematically for the first time (up to 99% enantiomeric excess). The results demonstrated that the steric size of cycloalkyl groups has a significant influence on the reaction outcomes. The first stereoselective formation of a selection of cyclohexyl heteroaryl alcohols of up to 97% enantiopurity was realized
Method of regulating the growth of aquatic weeds with pyridine
申请人:Eli Lilly and Company
公开号:US04043790A1
公开(公告)日:1977-08-23
A method of regulating the growth of submerged and floating aquatic weeds which comprises adding a 2- or 4-substituted pyridinemethane or pyridinemethanol to a body of water containing the submerged and floating aquatic weeds to be regulated, in quantities sufficient to regulate the growth of the submerged and floating aquatic weeds therein. The disclosure also relates to novel compositions for carrying out the method.