A rhodium-catalyzed C–H functionalization with activated amides by decarbonylation has been developed. Notably, this is the first C–H arylation employing N-acylsaccharins as coupling partners to give biaryls in good to excellent yields. The highlight of the work is the high tolerance of functional groups such as formyl, ester, and vinyl and the use of a removable directing group.
coupled with aryl bromides in the presence of an iron catalyst, metallic magnesium, a diamine ligand and an organic dihalide oxidant at 0 °C. The use of a 1:1 mixture of tetrahydrofuran and 1,4‐dioxane is essential for this CH bond activation reaction. The reaction has wider scope of the substrate compared with the reaction using a separately prepared Grignard reagent, and proceeds with lower catalyst
Direct arylation of the ortho‐CHbond of an aryl pyridine or an aryl imine with an aryl Grignard reagent has been achieved by using an iron‐diamine catalyst and a dichloroalkane as an oxidant in a short reaction time (e.g., 5 min) under mild conditions (0 °C). The use of an aromatic co‐solvent, such as chlorobenzene and benzene, and slow addition of the Grignard reagent are essential for the high
Rhodium-Catalyzed Cross-Coupling Reactions of Carboxylate and Organoboron Compounds via Chelation-Assisted C–C Bond Activation
作者:Jingjing Wang、Bowen Liu、Haitao Zhao、Jianhui Wang
DOI:10.1021/om300994j
日期:2012.12.24
A new rhodium-catalyzed decarbonylated coupling reaction of ethyl benzo[h]quinoline-10-carboxylate and organoboroncompounds that occurs through chelation-assisted sp2 C–COOEt bond activation was described. In this system CuCl played a very important role, and a five-membered rhodacycle was also involved as a key intermediate. Various functionalities were compatible in the reaction, and the desired
描述了一种新的铑催化的苯并[ h ]喹啉-10-羧酸乙酯与有机硼化合物的脱羰偶联反应,该反应通过螯合辅助的sp 2 C-COOEt键活化而发生。在该系统中,CuCl发挥了非常重要的作用,并且五元罗丹环也作为关键中间体参与其中。在反应中各种官能团是相容的,并且以良好至优异的产率获得了所需的产物。还已经使用Rh(I)模型催化剂对该反应机理进行了DFT计算。
Recyclable Solid Ruthenium Catalysts for the Direct Arylation of Aromatic CH Bonds
Environmentally benign catalyst: A PPh3‐modified Ru/CeO2 catalyst showed excellent catalytic activity toward directCHarylation by using various aryl chlorides in the reaction (see scheme). The catalyst was found to act heterogeneously and could be recycled without significant loss of activity.
对环境无害的催化剂:通过在反应中使用各种芳基氯化物,PPh 3改性的Ru / CeO 2催化剂对直接CH芳基化反应表现出出色的催化活性(请参阅方案)。发现该催化剂具有异质作用,可以循环使用而不会显着降低活性。