最近,我们报道了基于氧杂蒽酮(CDXs)的手性衍生物的液相色谱(LC)的新手性固定相(CSP)的开发。基于最有前途的CDX选择器,成功地从合适的功能化小分子(包括one吨酮和二苯甲酮衍生物)制备了12种新的CSP。将包含一个,两个,三个或四个手性部分的手性选择剂共价键合到色谱载体上,并进一步填充到LC不锈钢柱(150×2.1 mm ID)中。使用不同种类的手性化合物通过LC评估了新CSP的对映选择性。在评估新的CSP时观察到了对映体分离某些CDX的特异性。除了,通过使用分子对接方法的计算研究对手性识别机理进行了评估,这与色谱参数相符。X射线分析用于建立手性选择器3D结构。
Asymmetric Imine Hydroboration Catalyzed by Chiral Diazaphospholenes
作者:Matt R. Adams、Chieh-Hung Tien、Robert McDonald、Alexander W. H. Speed
DOI:10.1002/anie.201709926
日期:2017.12.22
first use of diazaphospholenes as chiral catalysts has been demonstrated with enantioselective iminehydroboration. A chiral diazaphospholene prepared in a simple three‐step synthesis from commercial materials has been shown to achieve the highest enantioselectivity for the hydroboration of alkyl imines with pinacolborane reported to date. Enantiomer ratios of up to 88:12 were obtained with low (2 mol %)
Fast continuous alcohol amination employing a hydrogen borrowing protocol
作者:Ricardo Labes、Carlos Mateos、Claudio Battilocchio、Yiding Chen、Paul Dingwall、Graham R. Cumming、Juan A. Rincón、Maria José Nieves-Remacha、Steven V. Ley
DOI:10.1039/c8gc03328e
日期:——
A continuous flow method for the direct conversion of alcohols to amines via a hydrogen borrowing approach is reported. The method utilises a low loading (0.5%) of a commercial catalyst system ([Ru(p-cymene)Cl2]2 and DPEPhos), reagent grade solvent and is selective for primary alcohols. Successful methylation of amines using methanol and the direct dimethylamination of alcohols using commercial dimethylamine
N-Benzylamines are prepared by a process in which
(i) in a first step, a benzaldehyde is reacted with a primary amine to give the imine and
(ii) in a second step, the imine is hydrogenated with hydrogen in the presence of a catalyst containing one or more metals of groups 8 to 10 of the Periodic Table of the Elements to give the N-benzylamine,
wherein the iminization (i) is carried out in a water-miscible solvent and the resulting water of reaction is not removed, and the hydrogenation (ii) is carried out in the imine solution obtained in the iminization (i) and containing water of reaction.
N-苄胺是通过以下过程制备的:
(i) 在第一步中,苯甲醛与一级胺反应生成亚胺,
(ii) 在第二步中,在元素周期表8至10族中的一个或多个金属催化剂存在下,将亚胺与氢气加氢反应生成N-苄胺,
其中亚胺化反应(i)在水溶性溶剂中进行,生成的反应水不被去除,而加氢反应(ii)在亚胺化反应(i)中获得的亚胺溶液中进行,其中含有反应水。
Synthetic Modifiers for Platinum in the Enantioselective Hydrogenation of Ketopantolactone: A Test for the Mechanistic Models of Ketone Hydrogenation
Various derivatives of (R)-1-(1-naphthyl)ethylamine have been synthesized and tested as chiral modifiers of Pt/alumina in the enantioselectivehydrogenation of ketopantolactone. The best modifiers (ee up to 79%) possess an ester function in the α-position to the amino group. The modifiers performed far better in AcOH than in toluene, indicating that protonation of the N atom is important in enantioselection
New chiral stationary phases for liquid chromatography based on small molecules: Development, enantioresolution evaluation and chiral recognition mechanisms
作者:Ye' Zaw Phyo、Joana Teixeira、Maria Elizabeth Tiritan、Sara Cravo、Andreia Palmeira、Luís Gales、Artur M.S. Silva、Madalena M.M. Pinto、Anake Kijjoa、Carla Fernandes
DOI:10.1002/chir.23142
日期:2020.1
the development of new chiralstationaryphases (CSPs) for liquidchromatography (LC) based on chiral derivatives of xanthones (CDXs). Based on the most promising CDX selectors, 12 new CSPs were successfully prepared starting from suitable functionalized small molecules including xanthone and benzophenone derivatives. The chiral selectors comprising one, two, three, or four chiral moieties were covalently
最近,我们报道了基于氧杂蒽酮(CDXs)的手性衍生物的液相色谱(LC)的新手性固定相(CSP)的开发。基于最有前途的CDX选择器,成功地从合适的功能化小分子(包括one吨酮和二苯甲酮衍生物)制备了12种新的CSP。将包含一个,两个,三个或四个手性部分的手性选择剂共价键合到色谱载体上,并进一步填充到LC不锈钢柱(150×2.1 mm ID)中。使用不同种类的手性化合物通过LC评估了新CSP的对映选择性。在评估新的CSP时观察到了对映体分离某些CDX的特异性。除了,通过使用分子对接方法的计算研究对手性识别机理进行了评估,这与色谱参数相符。X射线分析用于建立手性选择器3D结构。