A Highly Active Catalyst for Pd-Catalyzed Amination Reactions: Cross-Coupling Reactions Using Aryl Mesylates and the Highly Selective Monoarylation of Primary Amines Using Aryl Chlorides
作者:Brett P. Fors、Donald A. Watson、Mark R. Biscoe、Stephen L. Buchwald
DOI:10.1021/ja8055358
日期:2008.10.15
reactivity for C-N cross-coupling reactions is reported. This catalyst system enables the use of arylmesylates as a coupling partner in C-N bond-forming reactions. Additionally, the use of BrettPhos permits the highly selective monoarylation of an array of primary aliphatic amines and anilines at low catalyst loadings and with fast reaction times, including the first monoarylation of methylamine. Lastly
with one or two equivalents of -butyllithum and various dienes (furans, pyrroles, cyclopentadienes, fulvenes) to form mono- or bis-cycloadducts. Highly substituted arenes can be obtained by removing the oxygen or nitrogens bridges from the furan or pyrrole adducts. By choice of conditions, two identical or two different rings can be fused to the di-aryne epuivalent. Improved short syntheses of permethylnaphthalene
Halogenation Using Quaternary Ammonium Polyhalides. XIV. Aromatic Bromination and Iodination of Arenes by Use of Benzyltrimethylammonium Polyhalides–Zinc Chloride System
The reaction of arenes with benzyltrimethylammonium tribromide or benzyltrimethylammonium dichloroiodate in acetic acid in the presence of ZnCl2 at room temperature or at 70 °C gave bromo- or iodo-substituted arenes in good yield, respectively.
Use of Tunable Ligands Allows for Intermolecular Pd-Catalyzed C−O Bond Formation
作者:Andrei V. Vorogushin、Xiaohua Huang、Stephen L. Buchwald
DOI:10.1021/ja050471r
日期:2005.6.1
Pd-catalyzed C-O coupling reactions of aryl halides with primary and secondary alcohols by promoting reductive elimination at the expense of beta-hydride elimination. The key to their success is the ability to match the size of the ligand to that of the combination of substrates. The efficient coupling of a number of unactivated aryl chlorides and bromides with cyclic and acyclicsecondary alcohols was achieved
庞大的联芳基膦配体通过促进还原消除以消除 β-氢化物为代价,促进了 Pd 催化的芳基卤化物与伯醇和仲醇的 CO 偶联反应。它们成功的关键是能够将配体的大小与底物组合的大小相匹配。实现了许多未活化的芳基氯化物和溴化物与环状和非环状仲醇的有效偶联。这包括首次在 Pd 催化的偶联过程中偶联烯丙醇。
Pd-Catalyzed N-Arylation of Secondary Acyclic Amides: Catalyst Development, Scope, and Computational Study
作者:Jacqueline D. Hicks、Alan M. Hyde、Alberto Martinez Cuezva、Stephen L. Buchwald
DOI:10.1021/ja9044357
日期:2009.11.25
efficient N-arylation of acyclic secondary amides and related nucleophiles with aryl nonaflates, triflates, and chlorides. This method allows for easy variation of the aromatic component in tertiary aryl amides. A new biaryl phosphine with P-bound 3,5-(bis)trifluoromethylphenyl groups was found to be uniquely effective for this amidation. The critical aspects of the ligand were explored through synthetic, mechanistic
我们报告了无环仲酰胺和相关亲核试剂与芳基九氟甲磺酸酯、三氟甲磺酸酯和氯化物的有效 N-芳基化。这种方法可以很容易地改变叔芳基酰胺中的芳香族成分。发现具有 P 键合 3,5-(双) 三氟甲基苯基的新联芳基膦对这种酰胺化反应特别有效。通过合成、机械和计算研究探索了配体的关键方面。配体的系统变异揭示了 (1) 与磷相邻的“顶环”芳香碳上的甲氧基和 (2) 两个高度吸电子的 P 键合 3,5-(双) 三氟甲基苯基的重要性. 计算研究表明,配体的缺电子性质对于促进酰胺与 LPd(II)(Ph)(X) 中间体的结合很重要。