C−H Insertion as a Key Step to Spiro-Oxetanes, Scaffolds for Drug Discovery
作者:Simon M. Nicolle、Andrew Nortcliffe、Hannah E. Bartrum、William Lewis、Christopher J. Hayes、Christopher J. Moody
DOI:10.1002/chem.201703746
日期:2017.10.4
A new route to spiro‐oxetanes, potential scaffolds for drug discovery, is described. The route is based on the selective 1,4‐C−H insertion reactions of metallocarbenes, generated from simple carbonyl precursors in flow or batch mode, to give spiro‐β‐lactones that are rapidly converted into spiro‐oxetanes. The three‐dimensional and lead‐like properties of spiro‐oxetanes are illustrated by the conversion
Ambient and aerobic carbon–carbon bond cleavage toward α-ketoester synthesis by transition-metal-free photocatalysis
作者:Qing Yu、Yating Zhang、Jie-Ping Wan
DOI:10.1039/c9gc01357a
日期:——
available enaminones enabling efficient synthesis of α-ketoesters is developed. The reactions showing general tolerance to the reactions of primary and secondaryalcohols proceed well under air via Rose Bengal (RB)-based photocatalysis. Particularly, this mild synthetic method has been discovered to tolerate various polyhydroxylated substrates such as phenolic alcohol, diols and triols with an excellent
catalyzed controlled oxidation of terminal CC alkynes to α-keto esters and quinoxalines via formation of phenylglyoxals as stable intermediates, under mild conditions by using molecular O2 as a sustainable oxidant. The current copper catalysed photoredox method is simple, highly functional group compatible with a broad range of electron rich and electron poor aromatic alkynes as well as aliphatic alcohols
在此,我们报道了一种在温和条件下使用分子 O 2通过形成苯基乙二醛作为稳定的中间体,在可见光诱导的铜催化下,末端 C C 炔烃可控氧化为 α-酮酯和喹喔啉的方法。作为一种可持续的氧化剂。目前的铜催化光氧化还原方法简单、官能团高,与广泛的富电子和贫电子芳烃以及脂肪醇(1°、2°和3°醇)相容,为制备α-酮酯(43 个例子)、喹喔啉和萘醌的产率高于文献报道的热工艺。此外,该产品的合成效用已在两种生物活性分子的合成中得到证明,即大肠杆菌DHPS 抑制剂和 CFTR 活化剂,使用当前的光氧化还原过程。此外,我们将该方法应用于杂环化合物(喹喔啉,一种 FLT3 抑制剂)的一锅合成,方法是用邻苯二胺。也可以分离中间体苯乙二醛并进一步与内部炔烃反应以形成萘醌。这个过程可以很容易地放大到克级。
Heterogeneous Esterification from α-Hydroxy Ketone and Alcohols through a Tandem Oxidation Process over a Hydrotalcite-Supported Bimetallic Catalyst
Heterogeneous aerobic oxidative esterification between a-hydroxy ketone and alcohols catalyzed by a hydrotalcite-supported bimetallic catalyst (CuMn/HT) using O-2 as a green oxidant was achieved. Recyclable CuMn/HT exhibits high catalytic activity due to increased content of oxygen vacancies and a newly generated CuMn2O4 crystal phase. This clean esterification proceeds through a tandem oxidation process in the absence of any additives and ligands and affords alpha-keto esters in good to excellent yields. Moreover, the catalytic system tolerates complicated bioactive molecules as raw materials and can be performed on a multigram scale.
Crystallisation and Purification of Glycopyrronium Bromide
申请人:Baxter Andrew Douglas
公开号:US20080227988A1
公开(公告)日:2008-09-18
A method for the production of crystalline glycopyrronium bromide, comprises the reaction of glycopyrronium base with methyl bromide in a solvent, in which the solvent is selected such that the diastereoisomeric ratio of the product favours the R, S and S, R diastereoisomers over the R, R, and S, S diastereoisomers, and separating the desired diastereoisomers by one or more controlled crystallisation steps. This method gives a product having a particle size of narrow distribution.