已开发出由铱-二氟配合物催化的各种2-烷基和2-芳基取代的喹喔啉衍生物的一般不对称氢化反应。在温和的反应条件下,可以以高收率和高达95%的良好至优异的对映选择性获得相应的生物学上相关的2-取代-1,2,3,4-四氢喹喔啉单元。催化剂比为S / C = 1000且以克为单位,Ir-二氟膦配合物的催化活性得以保持,并显示出其潜在价值。最后,我们证明了我们的方法在化合物(S)-9的合成中的应用,该化合物是胆固醇酯转移蛋白(CETP)的抑制剂。
B(C6F5)3-Catalyzed tandem cyclization/hydrosilylation for the step-economical construction of 1,2,3,4-tetrahydroquinoxalines from readily available starting materials has been developed.
A process for producing an optically active amine compound, characterized by asymmetrically hydrogenating a prochiral carbon-nitrogen double bond in the presence of a ruthenium complex represented by general formula (1) or (2) (wherein P
represents an optically active diphosphine, X represents an anionic group, and Ar represents an optionally substituted arylene group).
Water as a hydride source: A new pathway to form metal–hydride bonds has been developed through the reaction of easily available metal–silyl compounds with water. This method has been successfully applied to asymmetrichydrogenation of heteroaromatic compounds with up to 93 % ee under mild autoclave‐free conditions (see scheme).
Asymmetric hydrogenation of quinolines activated by Brønsted acids
作者:Duo-Sheng Wang、Yong-Gui Zhou
DOI:10.1016/j.tetlet.2010.04.004
日期:2010.6
Enantioselective hydrogenation of quinolines and quinoxalines catalyzed by iridium/diphosphine complex with catalytic amount of Brønsted acid as activator was developed. In the presence of piperidine·TfOH as the activator, full conversions and up to 92% ee were obtained.
terminal epoxides into valuable 1,2,3,4-tetrahydroquinoxalines in a highly enantioselective fashion. This procedure operates through relay zinc and iridiumcatalysis, and achieves redox-neutral and stereoconvergent production of valuable chiral heterocycles from racemic starting materials with water as the only side product. The use of commercially available reagents and catalysts and a convenient procedure