We describe the development of Pd–PHOX-catalysed enantioselective couplings of internal dienes with malononitrile and other activated C-pronucleophiles. Reactions are dramatically accelerated by the addition of Et3N·HBArF4 as a Brønsted acid co-catalyst, enabling a suite of products bearing a variety of alkyl substituents at the stereogenic carbon to be prepared. A series of mechanism-oriented experiments
我们描述了 Pd-PHOX 催化的内部二烯与
丙二腈和其他活化的 C-亲核试剂的对映选择性偶联的发展。添加 Et 3 N·HBAr F 4作为布朗斯台德酸助催化剂可显着加速反应,从而能够制备出一系列在立体碳上带有各种烷基取代基的产物。一系列以机理为导向的实验揭示了催化循环的关键方面以及非配位BAr F 4反离子的重要性,不仅促进了内部二烯的反应,而且还促进了先前不反应的亲核试剂向末端二烯的添加。