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
Nickel-Catalyzed Csp<sup>2</sup>–Csp<sup>3</sup>Bond Formation via C–F Bond Activation
作者:Yee Ann Ho、Matthias Leiendecker、Xiangqian Liu、Chengming Wang、Nurtalya Alandini、Magnus Rueping
DOI:10.1021/acs.orglett.8b02351
日期:2018.9.21
A nickel-catalyzed cross coupling of aryl fluorides via C–Fbondactivation has been developed. The alkylation method allows selective replacement of aryl fluorides by alkyl groups and enables the synthesis of diverse and otherwise difficult to access scaffolds in good yields.
An efficient room-temperature Pd-catalyzed Suzuki–Miyaura cross-coupling reaction of aryl-boronic acids with aryl chlorides is communicated here. The Pd(OAc)2/NiXantphos catalyst system enables the coupling reaction at room temperature in good to excellent yields (average yield >90%).
Copper-Catalyzed <i>ipso</i>-Borylation of Fluoroarenes
作者:Takashi Niwa、Hidenori Ochiai、Takamitsu Hosoya
DOI:10.1021/acscatal.7b01448
日期:2017.7.7
studies suggest that the reaction proceeds via an SRN1mechanism involving a single-electron-transfer (SET) process and not via the typical SNAr mechanism. This method differs from the previously reported nickel/copper-cocatalyzed system in terms of scope of the substrate and has exhibited good scalability. Double and triple ipso-borylations of several di- and trifluoroarenes have been also achieved
本位fluoroarenes的-Borylation已经使用空气稳定的铜配合物作为催化剂来实现的。机理研究表明,反应是通过涉及单电子转移(SET)过程的S RN 1机理而不是通过典型的S N Ar机理进行的。该方法在基材范围方面与先前报道的镍/铜共催化体系不同,并且具有良好的可扩展性。双重和三重IPSO几个二和trifluoroarenes的-borylations也已被有效地实现,从而提高了该方法的综合效用。
Dual Nickel-/Palladium-Catalyzed Reductive Cross-Coupling Reactions between Two Phenol Derivatives
作者:Baojian Xiong、Yue Li、Yin Wei、Søren Kramer、Zhong Lian
DOI:10.1021/acs.orglett.0c02165
日期:2020.8.21
Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance of phenols. Here, we report a dual nickel-/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryltriflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60