Solvent and Base in One: Tetra-<i>n</i>
-butylammonium Acetate as a Multi-Purpose Ionic Liquid Medium for Ru-Catalyzed Directed Mono- and Di-<i>o</i>
-C-H Arylation Reactions
作者:Ya-Ling Zou、Zhen-Yu Wang、Yin-Mao Feng、You-Gui Li、Eric Assen B. Kantchev
DOI:10.1002/ejoc.201701022
日期:2017.11.16
Bu4NOAc can be a multi-purpose medium for a Ru-catalyzed directed o-C–H arylation reaction with functionalized aryl bromides. Acetate plays the role of base and Bu4N salts (excess acetate and side product bromide) behave as ionicliquids. The medium is compatible with both RuCl3·xH2O (major product: di-arylation) and [RuCl2(p-cymene)]2/(p-Tol)3P catalytic systems (major product: mono-arylation).
Bu 4 NOAc可以是多官能团介质,用于Ru催化的与官能化芳基溴化物进行的定向o -C–H芳基化反应。乙酸盐起碱的作用,Bu 4 N盐(过量的乙酸盐和副产物溴化物)起离子液体的作用。该介质与RuCl 3 · x H 2 O(主要产物:二芳基化)和[RuCl 2(p- cymene)] 2 /(p -Tol)3 P催化系统兼容(主要产物:单芳基化) 。
Controlling Site Selectivity in Pd-Catalyzed Oxidative Cross-Coupling Reactions
作者:Thomas W. Lyons、Kami L. Hull、Melanie S. Sanford
DOI:10.1021/ja1097918
日期:2011.3.30
This paper presents a detailed investigation of the factors controlling site selectivity in the Pd-mediated oxidative coupling of 1,3-disubstituted and 1,2,3-trisubstituted arenes (aryl -H) with cyclometalating substrates (L similar to C-H). The influence of both the concentration and the steric/electronic properties of the quinone promoter are studied in detail. In addition, the effect of steric/electronic modulation of the carboxylate ligand is discussed. Finally, we demonstrate that substitution of the carboxylate for a carbonate X-type ligand leads to a complete reversal in site selectivity for many arene substrates. The origins of these trends in site selectivity are discussed in the context of the mechanism of Pd-catalyzed oxidative cross-coupling.