An efficient palladium catalyzed Mizoroki–Heck cross-coupling in water
作者:Sanjay N. Jadhav、Chandrashekhar V. Rode
DOI:10.1039/c7gc02869e
日期:——
Pd-catalysed Mizoroki–Heck coupling reaction was successfully performed in water in the absence of any additives under aerobic conditions. The various key reaction parameters that affect the yield of the desired cross-coupling product were optimized. The Pd(PPh3)4/Et3N/H2O/98 °C catalyst system was found to be highly active (TOF = 12 to 14 h−1) towards achieving excellent yield of the Mizoroki–Heck coupling
在有氧条件下,在没有任何添加剂的情况下,水中成功地进行了均相Pd催化的Mizoroki-Heck偶联反应。优化了影响所需交叉偶联产物收率的各种关键反应参数。发现Pd(PPh 3)4 / Et 3 N / H 2 O / 98°C催化剂体系具有很高的活性(TOF = 12至14 h -1),可实现出色的Mizoroki–Heck偶联产物的收率。在最短的反应时间内,吸电子以及给电子的芳基溴化物和氯化物种类繁多。钯(PPh 3)4对Mizoroki-Heck偶联反应过程中的催化剂失活进行了研究,并发展了实现十倍Pd-金属可循环性而又没有明显损失其活性的策略。因此,提出的机制提供了在水性介质中接触各种烯烃的途径,从而使该协议变得环保。
Catalytic Asymmetric Synthesis with Rh−Diene Complexes: 1,4-Addition of Arylboronic Acids to Unsaturated Esters
作者:Jean-François Paquin、Corey R. J. Stephenson、Christian Defieber、Erick M. Carreira
DOI:10.1021/ol051533l
日期:2005.8.1
route to enantioenriched tert-butyl 3,3-diarylpropanoates is presented. These useful building blocks are prepared via an asymmetricrhodium-catalyzedconjugateaddition of arylboronic acids to unsaturated tert-butyl esters in the presence of chiral dienes as ligands. The addition of both electron-poor and electron-rich boronic acids proceeds smoothly with various enoates in 63-90% yield with high enantioselectivites
Rhodium-Catalyzed Heck-Type Coupling of Boronic Acids with Activated Alkenes in an Aqueous Emulsion
作者:Mark Lautens、John Mancuso、Harpreet Grover
DOI:10.1055/s-2004-829161
日期:——
Intermolecular couplings between arylboronic acids and activated alkenes catalyzed by a water-soluble tert-butyl amphosrhodium complex were found to progress at room temperature and generated Heck-type products with high yields and excellent selectivity. Substitution on the alkene component encouraged the formation of products arising from a conjugate addition-protonation process. In the case of Heck
Ce0·98Pd0·02O2-δ: Recyclable, ligand free palladium(II) catalyst for Heck reaction
作者:S R SANJAYKUMAR、BHASKAR DEVU MUKRI、SATISH PATIL、GIRIDHAR MADRAS、M S HEGDE
DOI:10.1007/s12039-011-0103-6
日期:2011.1
Palladium substituted in cerium dioxide in the form of a solid solution, Ce0·98 Pd0·02 O1·98 is a new heterogeneous catalyst which exhibits high activity and 100% trans-selectivity for the Heck reactions of aryl bromides including heteroaryls with olefins. The catalytic reactions work without any ligand. Nano-crystalline Ce0·98 Pd0·02 O1·98 is prepared by solution combustion method and Pd is in +2 state. The catalyst can be separated, recovered and reused without significant loss in activity.