Asymmetric organocatalytic reduction of ketimines with catecholborane employing a N-triflyl phosphoramide Brønsted acid as catalyst
作者:Dieter Enders、Andreas Rembiak、Matthias Seppelt
DOI:10.1016/j.tetlet.2012.11.055
日期:2013.2
The first asymmetric reduction of ketimines with catecholborane employing an enantiopure N-triflyl phosphoramide as the organocatalyst has been developed. Five mole % of the catalyst provides the corresponding secondary amines in very good to almost quantitative yields and good enantioselectivities up to 86:14 e.r. under mild reaction conditions.
Chiral aliphaticamine compounds exhibit a range of physiological activities, making them highly sought-after in the pharmaceutical industry and biological research. One notable obstacle in studying these compounds stems from the pronounced steric hindrance surrounding the nitrogen atom. This characteristic often leads to a weak affinity of acyclic secondary amines for molecular probes, making their
手性脂肪胺化合物表现出一系列的生理活性,使其在制药工业和生物研究中备受追捧。研究这些化合物的一个显着障碍源于氮原子周围明显的空间位阻。这一特性通常导致无环仲胺对分子探针的亲和力较弱,使得它们的手性辨别变得复杂。为了应对这一挑战,我们的研究推出了一种新型19 F 标记探针,能够识别和区分这些无环仲胺的对映体。通过策略性地合并单个氟原子作为19 F 标记,我们成功地减少了结合位点的空间位阻。这种改变增强了探针对体积较大的分析物的亲和力。为了证明其有效性,我们已成功地将我们的探针用于相关药物的手性分析,准确地确定了它们的对映体组成。
Rhodium(<scp>I</scp>)–sulfonated-bdpp catalysed asymmetric hydrogenation of imines in aqueous–organic two-phase solvent systems
The imines ArC(Me)NCH2Ph (Ar = Ph, 2-MeO-C6H4, 3-MeO-C6H4, 4-MeO-C6H4) are hydrogenated to the corresponding amines with extremely high enantioselectivities up to 96% under very mild conditions, using rhodium complexes associated with sulfonated bdpp.