Chiral-at-metal iridium complex for efficient enantioselective transfer hydrogenation of ketones
作者:Cheng Tian、Lei Gong、Eric Meggers
DOI:10.1039/c6cc00972g
日期:——
A bis-cyclometalated iridium(III) complex with metal-centered chirality catalyzes the enantioselectivetransferhydrogenation of ketones with high enantioselectivities at low catalyst loadings down to 0.002 mol%. Importantly, the rate of catalysis...
Iron-catalyzed asymmetric hydrosilylation of ketones
作者:Ziqing Zuo、Lei Zhang、Xuebing Leng、Zheng Huang
DOI:10.1039/c5cc00612k
日期:——
iminopyridine-oxazoline (IPO) ligands have been synthesized. The most sterically hindered iron catalyst exhibits excellent activity (up to 99% yield) and high enantioselectivity (up to 93% ee) in asymmetrichydrosilylation of aryl ketones.
Fine tuning of molecular and supramolecular properties of simple trianglimines – the role of the functional group
作者:J. Gajewy、J. Szymkowiak、M. Kwit
DOI:10.1039/c6ra06095a
日期:——
affected by the nature and chirality of the dopant. The hexaimine macrocycles after reduction of the CN imine bonds formed trianglamines – useful chiral ligands in stereoselective synthesis. The Zn–trianglamine complexes were employed as catalysts for asymmetric hydrosilylation of prochiral ketones, providing products of enantiomeric excess up to 98%. This remains the best result obtained for Zn–diamine
New C2-symmetric tetrafluorobenzobarreleneligands were prepared and applied successfully to the rhodium-catalyzedasymmetric addition of arylboronic acids to aromatic aldehydes giving chiral diarylmethanols in high yield with high enantioselectivity.
Synthesis of the bifunctional BINOL ligands and their applications in the asymmetric additions to carbonyl compounds
作者:Ying-Chuan Qin、Lan Liu、Michal Sabat、Lin Pu
DOI:10.1016/j.tet.2006.06.049
日期:2006.10
the diphenylzinc addition which often require the addition of a significant amount of diethylzinc with cooling (or heating) the reaction mixture in order to achieve high enantioselectivity, using (S)-8 needs no additive and gives excellent results at room temperature. (S)-8 in combination with diethylzinc and Ti(OiPr)4 can catalyze the highly enantioselective phenylacetylene addition to aromatic aldehydes
分别从BINOL和H 8 BINOL与吗啉代甲醇的反应中开发了双功能BINOL和H 8 BINOL配体(S)-6和(S)-8的高效一步合成方法。这些化合物的X射线分析表明它们在结构上有相似之处和不同之处。双功能H 8 BINOL(S)-8已发现对二苯基锌与许多脂族和芳族醛的反应具有很高的对映选择性,尤其是对于线性脂族醛而言,对映选择性最强的催化剂。与开发用于添加二苯锌的其他催化剂不同,该催化剂通常需要在冷却(或加热)的同时添加大量的二乙基锌以实现高对映选择性,使用(S)-8无需添加剂,在室温下可获得优异的结果温度。(S)-8与二乙基锌和Ti(O i Pr)4结合可以催化高度对映选择性的苯乙炔加成芳族醛。尽管对映选择性还不是很高,但它在室温下还可以促进苯乙炔向苯乙酮的添加。在不使用Ti(O i Pr)4和路易斯碱添加剂的情况下,(S)-8与二乙基锌结合可以催化丙酸甲酯与醛的反应,形成高官能度