Asymmetric synthesis of β-fluoroaryl-β-amino acids
摘要:
The conjugate addition of lithium (R)-N-benzyl-N-(alpha-methylbenzyl)amide to a range of beta-fluoroaryl-alpha,beta-unsaturated esters gave the corresponding beta-amino esters with high diastereoselectivity and in good isolated yields. Sequential treatment of the resultant beta-fluoroaryl-beta-amino esters under optimised hydrogenolysis conditions, followed by ester hydrolysis with 2.0 M aq HCl, provided access to a range of beta-fluoroaryl-beta-amino acids in good yield. (c) 2012 Elsevier Ltd. All rights reserved.
DOI:
10.1016/j.tetasy.2012.07.001
作为产物:
描述:
3-氟肉桂酸 、 N,N-二甲基甲酰胺二叔丁基缩醛 在
水 、 碳酸氢钠 、 Brine 、 magnesium sulfate 、 crude product 、 2-甲基戊烷 、 乙酸乙酯 作用下,
以
甲苯 为溶剂,
反应 4.5h,
以2% ethyl acetate in isohexane) to give the sub-title compound as a liquid (3.7 g, 64%)的产率得到(E)-3-(3-氟苯基)丙烯酸叔丁酯
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
Imidazolylidene carbene ligated palladium catalysis of the Heck reaction in the presence of air
作者:Jingping Liu、Yuanhong Zhao、Yongyun Zhou、Liang Li、Tony Y. Zhang、Hongbin Zhang
DOI:10.1039/b306715g
日期:——
Five 1,3-disubstituted imidazolium salts were synthesized. Their Heck reaction activities were evaluated. A convenient, efficient and high yielding procedure based on these compounds for the arylation of olefins was developed. Heck reactions mediated by these palladium–N-heterocyclic carbene complexes were conducted under air and even in the presence of several common oxidants.
elevated-temperature conditions, allowing its recovery after reaction completion and recycling. The application of air- and moisture-stable dinuclear palladium(I) complex [Pd(μ-I)(Pt-Bu3)]2 as an efficient catalyst for the Heck cross-coupling reaction of aryl iodides and bromides with acrylates and styrenes is described. The developed protocol is robust and operationally simple and shows a high functional-group
摘要 空气和水分稳定的双核钯(I)配合物[Pd(μ-I)(P t -Bu 3)] 2作为芳基碘化物和溴化物与丙烯酸酯和丙烯酸的Heck交叉偶联反应的有效催化剂的应用。描述了苯乙烯。所开发的协议功能强大且操作简单,并且具有很高的功能组容限。所使用的钯(I)二聚体催化剂在这些亲核以及高温条件下具有很高的耐用性,可以在反应完成并循环使用后回收。 空气和水分稳定的双核钯(I)配合物[Pd(μ-I)(P t -Bu 3)] 2作为芳基碘化物和溴化物与丙烯酸酯和丙烯酸的Heck交叉偶联反应的有效催化剂的应用。描述了苯乙烯。所开发的协议功能强大且操作简单,并且具有很高的功能组容限。所使用的钯(I)二聚体催化剂在这些亲核以及高温条件下具有很高的耐用性,可以在反应完成并循环使用后回收。
Thermodynamic Understanding of an Aza-Michael Reaction Enables Five-Step Synthesis of the Potent Integrin Inhibitor MK-0429
作者:Anya Gupta、Matthew L. Condakes
DOI:10.1021/acs.joc.1c02375
日期:2021.12.3
strategy for the aza-Michael addition of nucleophilic heterocycles into β-substituted acrylates using potassium tert-butoxide as catalyst. Demonstrating that the reaction is under thermodynamic control underpins optimization efforts and enables rapid exploration of the substrate scope, with yields ranging from 55% to 94%. We further leverage these lessons in a significantly shortened synthesis of MK-0429
Non‐Chelate‐Assisted Palladium‐Catalyzed Aerobic Oxidative Heck Reaction of Fluorobenzenes and Other Arenes: When Does the C−H Activation Need Help?
作者:Francisco Villalba、Ana C. Albéniz
DOI:10.1002/adsc.202100677
日期:2021.10.19
sole oxidant and no redox mediator. Arenes with either electron-donating or electron-withdrawing groups can be functionalized in this way. Experimental data on the reaction with toluene as the model arene shows that the C−Hactivation step is turnover limiting and that the ligand structure is crucial to facilitate the reaction, which supports the involvement of the pyridone fragment in the C−H activation