A polystyrene-supported 9-amino(9-deoxy)epi quinine derivative for continuous flow asymmetric Michael reactions
作者:Javier Izquierdo、Carles Ayats、Andrea H. Henseler、Miquel A. Pericàs
DOI:10.1039/c5ob00325c
日期:——
derivative catalyzes Michael reactions affording excellent levels of conversion and enantioselectivity using different nucleophiles and structurally diverse enones. The highly recyclable, immobilized catalyst has been used to implement a single-pass, continuous flow process (residence time: 40 min) that can be operated for 21 hours without significant decrease in conversion and with improved enantioselectivity
Mixed Phosphane η<sup>5</sup>-CpRuCl(PR<sub>3</sub>)<sub>2</sub>Complexes as Ambifunctional Catalysts for Anti-Markovnikov Hydration of Terminal Alkynes
at C-6) for anti-Markovnikovhydration of terminal alkynes to aldehydes is retained when one heterocyclic ligand L is replaced by L' = PPh(3). Equal amounts of CpRuCl(PPh(3))(2) (1) and phosphane L in acetone solution equilibrate to a mixture of 1, CpRuCl(L)(PPh(3)) (2), and CpRuCl(L)(2) (3), which acts as highly active in situ catalyst for preparative anti-Markovnikovhydration of alkynes in water-rich
[CpRu(L)(2)(MeCN)]PF(6)(L = 2-diphenylphosphinopyridine 在 C-6 处具有庞大的基团)在一个杂环配体时保留了对末端炔烃的反马尔科夫尼科夫水合反应的催化活性L 由 L' = PPh(3) 代替。丙酮溶液中等量的 CpRuCl(PPh(3))(2) (1) 和磷烷 L 平衡为 1、CpRuCl(L)(PPh(3)) (2) 和 CpRuCl(L)(2) 的混合物) (3),在富水介质(2 mol % [Ru],60 °C,3-18 h in 4:1 (v/v ) 丙酮/水)。反应在 160 °C 下 <15 分钟内完成。
Synthesis of 3′-azido-3′-deoxythymidine (AZT)—Cinchona alkaloid conjugates via click chemistry: Toward novel fluorescent markers and cytostatic agents
作者:Dagmara Baraniak、Karol Kacprzak、Lech Celewicz
DOI:10.1016/j.bmcl.2010.11.127
日期:2011.1
Novel nucleoside–Cinchona alkaloid conjugates were synthesized using ‘click’ chemistry approach based on the copper(I) catalyzed Huisgen azide–alkyne cycloaddition. Two series of conjugates were prepared employing 3′-azido-3′-deoxythymidine (AZT) as the azide component and the four 10,11-didehydro Cinchonaalkaloids as well as their 9-O-propargyl ethers as the alkyne components. All obtained conjugates