in good to moderate yields, with elemental tellurium being formed as a black precipitate. A catalytic reduction-oxidation cycle involving a Ni or Co complex bearing an organotellurium moiety (RTe; R alkenyl, aryl, and alkyl) is proposed for the reaction. Palladium catalysts such as Pd(PPh3)4, PdCl2(PPh3)2, and PdCl2(PhCN)2 are revaled to be much less effective than the Ni and Co catalysts in both the
在NiCl 2(PPh 3)2,NiCl 2(Ph 2 PCH 2 CH 2 CH 2 PPh 2)或CoCl 2的存在下,一些烷基-和芳基-
碲化物与
格氏试剂(RMgBr; R芳基和烷基)反应(PPh 3)2在
四氢呋喃中作为催化剂或在溶剂中的
二乙基酯作为溶剂,以良好至中等的收率得到交叉偶联的产物与
碲化物的均相偶联产物,其中元素
碲形成为黑色沉淀物。对于该反应,提出了一种催化还原-氧化循环,该循环涉及包含带有有机
碲部分(RTe; R 6烯基,芳基和烷基)的Ni或Co配合物。
钯催化剂(例如Pd(PPh 3)4,PdCl 2(PPh 3)2和PdCl 2(PhCN)2)的收率和立体选择性均比Ni和Co催化剂差很多。