Chiral chromanols and their derivatives have been synthesized via a RuPHOX–Ru catalyzedasymmetrichydrogenation of chromones in high yields, >20 : 1 drs and with up to 99.9% ee. Control experiments show that the reaction undergoes two sequential asymmetrichydrogenation steps of the CC and CO double bonds. The reaction could be performed on a gram-scale with a relatively low catalyst loading (up to
通过RuPHOX-Ru催化色酮的不对称氢化,以高产率,> 20:1 drs和最高99.9%ee合成了手性苯甲酚及其衍生物。对照实验表明,该反应经历了C C和C O双键的两个连续的不对称氢化步骤。该反应可以以克级进行,具有相对较低的催化剂负载量(最高1000 S / C),并且所得产物可以转化为几种生物活性化合物。
Ruthenium-NHC-Catalyzed Asymmetric Hydrogenation of Flavones and Chromones: General Access to Enantiomerically Enriched Flavanones, Flavanols, Chromanones, and Chromanols
作者:Dongbing Zhao、Bernhard Beiring、Frank Glorius
DOI:10.1002/anie.201302573
日期:2013.8.5
Two to four! Readily available flavones and chromones were efficiently converted into four valuable chiral classes of O‐heterocycles—flavanones, chromanones, flavanols, and chromanols—by means of an enantioselective Ru/NHC‐catalyzed hydrogenation process (see scheme; NHC=N‐heterocyclic carbene, PCC=pyridinium chlorochromate).
C11 Modified Retrosteroids as Progesterone Receptor Modulator Compounds
申请人:Messinger Josef
公开号:US20080249075A1
公开(公告)日:2008-10-09
Retrosteroidal compounds corresponding to formula I, representing progesterone receptor modulators, and their production, and pharmaceutical preparations containing these compounds. These compounds are useful in the treatment of benign gynecological disorders such as endometriosis and uterine fibroids, as well as for female birth control and for hormone replacement therapy.
Facile photolytic demethoxylation of 3-methoxychromones
作者:Pranab Mandal、Asok Nath、R.V Venkateswaran
DOI:10.1016/0040-4020(96)00356-0
日期:1996.6
Photolysis of 3-methoxychromones in methanol furnishes chromones through extrusion of the methoxy function. A conjugate addition of methanol followed by a double methoxy elimination has been proposed to account for the cleavage product.