The Proline-Catalyzed Asymmetric Amination of Branched Aldehydes
作者:Thomas Baumann、Henning Vogt、Stefan Bräse
DOI:10.1002/ejoc.200600654
日期:2007.1
An efficient access to configurationally stable α,α-disubstituted α-amino aldehydes, oxazolidinones, and α-amino acids has been presented. Starting from simple and easily available racemic aldehydes, the α-aminated products were obtained using azodicarboxylates as the nitrogen source in up to 86 % ee and moderate to excellent yield. These products could further be converted both into the corresponding
Copper-Catalyzed Vinylogous Aerobic Oxidation of Unsaturated Compounds with Air
作者:Hai-Jun Zhang、Alexander W. Schuppe、Shi-Tao Pan、Jin-Xiang Chen、Bo-Ran Wang、Timothy R. Newhouse、Liang Yin
DOI:10.1021/jacs.8b01886
日期:2018.4.18
A mild and operationally simple copper-catalyzed vinylogous aerobic oxidation of β,γ- and α,β-unsaturated esters is described. This method features good yields, broad substrate scope, excellent chemo- and regioselectivity, and good functional group tolerance. This method is additionally capable of oxidizing β,γ- and α,β-unsaturated aldehydes, ketones, amides, nitriles, and sulfones. Furthermore, the
描述了一种温和且操作简单的铜催化乙烯基有氧氧化 β,γ-和 α,β-不饱和酯。该方法具有收率好、底物范围广、化学选择性和区域选择性好、官能团耐受性好等特点。该方法还能够氧化β,γ-和α,β-不饱和醛、酮、酰胺、腈和砜。此外,本催化体系适用于双乙烯基和三乙烯基氧化。发现四甲基胍 (TMG) 作为碱的作用至关重要,但我们也推测它可以作为三氟甲磺酸铜 (II) 的配体来生产活性铜 (II) 催化剂。进行的机械实验表明,通过烯丙基铜 (II) 物质存在一个合理的反应途径。最后,
Palladium-Catalyzed Allenamide Carbopalladation/Allylation with Active Methine Compounds
作者:Xiaoyi Zhu、Ruibo Li、Hequan Yao、Aijun Lin
DOI:10.1021/acs.orglett.1c01369
日期:2021.6.18
carbopalladation/allylation with active methine compounds has been developed. Various indoles and isoquinolinones bearing a quaternary carbon center were achieved with good efficiency, a broad substrate scope and good functional group tolerance. This reaction underwent cascade oxidative addition, carbopalladation, and allylicalkylation, and two new C–C bonds were formed in one pot.
The first nickel-catalyzed desymmetric hydrogenation has been achieved. With the Ni(OTf)2/(S,S)-Ph-BPE system, a series of γ,γ-disubstituted cyclohexadienones were transformed to the corresponding cyclohexenones with a chiral all-carbon quaternary center at the γ position in high yields (92% to 98%) and excellent enantioselectivities (92% to 99% ee). This catalytic system can also tolerate the desymmetric
首次实现了镍催化的不对称氢化。使用 Ni(OTf)2/(S,S)-Ph-BPE 系统,一系列 γ,γ-二取代环己二烯酮以高产率转化为相应的环己烯酮,其在 γ 位具有手性全碳四元中心( 92% 至 98%)和出色的对映选择性(92% 至 99% ee)。该催化体系还可以耐受螺碳环环己二烯酮的去对称反应,以产生相应的带有手性螺季碳的环己烯酮,收率高(94% 至 98%)和 ee 值(96% 至 99% ee)。此外,该方法为天然产物大麻吡酮 A 和 B 的中间体提供了一种高效、简洁的合成路线。