Ni/Cu-Catalyzed Defluoroborylation of Fluoroarenes for Diverse C–F Bond Functionalizations
摘要:
Ni/Cu-catalyzed transformation of fluroarenes to arylboronic acid pinacol esters via C-F bond cleavage has been achieved. Further versatile derivatization of an arylboronic ester has allowed for the facile two-step conversion of a fluoroarene to diverse functionalized arenes, demonstrating the synthetic utility of the method.
正交 C sp 2 –C sp 2偶联方案到无所不在的 Pd 催化类的发展将为密集功能化联芳基序的构建提供额外的模块化维度。在这种背景下,迫切需要鉴定用于选择性转化的有效官能团。尽管有机锗化合物通常被认为在均相催化中反应活性较低,但该报告揭示了芳基锗烷与芳烃在金催化下具有高效且正交的反应活性。该方法的特点是温和、使用空气和湿气稳定的金催化剂以及稳健性。我们的机理研究表明,芳基锗烷与 Au (I)和 Au (III)具有高度反应性。我们的计算数据表明,这种反应性的根源主要在于相对较低的键解离能,因此达到关键键激活过渡态的畸变能较低。
The reaction of readily generated silyl lithium reagents with various aryl fluorides to provide the corresponding aryl silanes is reported. DFT calculations reveal that the nucleophilicaromaticsubstitution of the fluoride anion by the silyl lithium reagent proceeds through concerted ipso substitution. In contrast to the classical nucleophilicaromaticsubstitution, this concerted ionic silyldefluorination
Potassium Trimethylsilanolate Enables Rapid, Homogeneous Suzuki−Miyaura Cross-Coupling of Boronic Esters
作者:Connor P. Delaney、Vincent M. Kassel、Scott E. Denmark
DOI:10.1021/acscatal.9b04353
日期:2020.1.3
Herein, a mild and operationally simple method for the Suzuki−Miyaura cross-coupling of boronicesters is described. Central to this advance is the use of the organic-soluble base, potassium trimethylsilanolate, which allows for a homogeneous, anhydrous cross-coupling. The coupling proceeds at a rapid rate, often furnishing products in quantitative yield in less than 5 min. By applying this method
作者:Liam T. Ball、Guy C. Lloyd-Jones、Christopher A. Russell
DOI:10.1126/science.1225709
日期:2012.9.28
Gently Coupled Linked aryl rings are found in a broad range of commercial chemical products. Currently, the most versatile synthetic route to this motif involves cross-coupling of one ring with a halide substituent to another ring with a boron or metal-based substituent. Recent research has focused on eliminating the need for one or both of these activating substituents, but for the most part, the
Gold-Catalyzed Oxidative Coupling of Arylsilanes and Arenes: Origin of Selectivity and Improved Precatalyst
作者:Liam T. Ball、Guy C. Lloyd-Jones、Christopher A. Russell
DOI:10.1021/ja408712e
日期:2014.1.8
substitution of the arylsilane and the arene by Au(III) precedes product-forming reductive elimination and subsequent cycle-closing reoxidation of the metal. Despite the fundamental mechanistic similarities between the two auration events, high selectivity is observed for heterocoupling (C-Si then C-H auration) over homocoupling of either the arylsilane or the arene (C-Si then C-Si, or C-H then C-H auration);
available, inexpensive pyrazole molecule to conduct C–C cross-coupling reactions at room temperature via a radical pathway. Using this method, an aryldiazonium salt has been coupled to a wide range of arenes and heteroarenes including benzene, mesitylene, thiophene, furan, benzoxazole to result the corresponding biaryl products. The full reaction mechanism is elucidated along with the crystallographic