Hu Zhiyong, Wei Xiao-Jing, Handelmann Jens, Seitz Ann-Katrin, Rodstein Ilja, Gessner Viktoria H, Gooßen Lukas J
Evonik Chair of Organic Chemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801, Bochum, Germany.
Chair of Inorganic Chemistry II, Fakultät für Chemie und Biochemie, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801, Bochum, Germany.
Angew Chem Int Ed Engl. 2021 Mar 15;60(12):6778-6783. doi: 10.1002/anie.202016048. Epub 2021 Jan 28.
The coupling of aryl chlorides with Reformatsky reagents is a desirable strategy for the construction of α-aryl esters but has so far been substantially limited in the substrate scope due to many challenges posed by various possible side reactions. This limitation has now been overcome by the tailoring of ylide-functionalized phosphines to fit the requirements of Negishi couplings. Record-setting activities were achieved in palladium-catalyzed arylations of organozinc reagents with aryl electrophiles using a cyclohexyl-YPhos ligand bearing an ortho-tolyl-substituent in the backbone. This highly electron-rich, bulky ligand enables the use of aryl chlorides in room temperature couplings of Reformatsky reagents. The reaction scope covers diversely functionalized arylacetic and arylpropionic acid derivatives. Aryl bromides and chlorides can be converted selectively over triflate electrophiles, which permits consecutive coupling strategies.
芳基氯与雷福尔马茨基试剂的偶联反应是构建α-芳基酯的理想策略，但由于各种可能的副反应带来诸多挑战，目前该反应的底物范围受到很大限制。现在，通过定制叶立德功能化膦以满足根岸偶联反应的要求，这一限制已被克服。使用主链带有邻甲苯基取代基的环己基-YPhos配体，在钯催化的有机锌试剂与芳基亲电试剂的芳基化反应中实现了创纪录的活性。这种高度富电子、体积庞大的配体使得芳基氯能够用于雷福尔马茨基试剂的室温偶联反应。反应范围涵盖了多种功能化的芳基乙酸和芳基丙酸衍生物。芳基溴化物和氯化物可以相对于三氟甲磺酸酯亲电试剂进行选择性转化，这允许采用连续偶联策略。
