Laboratory-Scale Membrane Reactor for the Generation of Anhydrous Diazomethane
作者:Doris Dallinger、Vagner D. Pinho、Bernhard Gutmann、C. Oliver Kappe
DOI:10.1021/acs.joc.6b01190
日期:2016.7.15
for the in situ on-demand generation of anhydrous solutions of diazomethane (CH2N2) avoiding distillation methods is presented. Diazomethane is produced by base-mediated decomposition of commercially available Diazald within a semipermeable Teflon AF-2400 tubing and subsequently selectively separated from the tubing into a solvent- and substrate-filled flask (tube-in-flask reactor). Reactions with CH2N2
提出了一种结构简单且坚固的半间歇设备,该设备可按需现场生成重氮甲烷(CH 2 N 2)无水溶液,而无需蒸馏方法。重氮甲烷是通过在半渗透性的Teflon AF-2400管道中通过碱介导的商品化Diazald分解产生的,然后选择性地将其从管道中分离成充满溶剂和基质的烧瓶(烧瓶中的管式反应器)。因此,可以在烧瓶中直接进行与CH 2 N 2的反应,而无需进行危险且费力的纯化操作,也无需操作员接触CH 2 N 2。该反应器已用于实验室规模的羧酸甲基化,α-氯酮和吡唑的合成以及钯催化的环丙烷化反应。在线FTIR技术的实施允许监控CH 2 N 2的产生及其消耗。另外,通过将几根膜管简单地包裹在烧瓶中,通过平行化(编号)可以获得更大的规模(每小时1.8 g重氮甲烷)。
Catalytic 1,3-Difunctionalization via Oxidative C–C Bond Activation
作者:Steven M. Banik、Katrina M. Mennie、Eric N. Jacobsen
DOI:10.1021/jacs.7b05160
日期:2017.7.12
reagents and can engage a variety of substituted cyclopropane substrates. Analysis of crystal and solution structures of several of the products reveal the consistent effect of 1,3-difluorides in dictating molecular conformation. The generality of the 1,3-oxidation strategy is demonstrated through the catalytic oxidative ring-opening of cyclopropanes for the synthesis of 1,3-fluoroacetoxylated products
Iron-Catalyzed Cyclopropanation in 6 M KOH with in Situ Generation of Diazomethane
作者:Bill Morandi、Erick M. Carreira
DOI:10.1126/science.1218781
日期:2012.3.23
simple iron porphyrin complex catalyzes the cyclopropanation of styrenes, enynes, and dienes under the demanding conditions [aqueous 6 molar potassium hydroxide (KOH) solution, open to air] necessary for the in situgeneration of diazomethane from a water-soluble diazald derivative. A biphasic reaction medium arising from the immiscibility of the olefin substrates with water appears essential to the
A process for the asymmetric aziridination of an alkene comprising treating the alkene with a sulfonyl azide, preferably trichloroethoxysulfonyl azide, in the presence of a cobalt(II) porphyrin.