1. Novel catalyst compositions, comprising
a) a palladium compound,
b) an anion of an acid with a pKa of less than 6,
c) a bidentate ligand of the general formula R₁R₂M-R-MR₃R₄, wherein M represents phosphorus, arsenic or antimony, R₁,R₂,R₃ and R₄ represent hydrocarbyl groups which may or may not be substituted with polar groups and R is a bivalent organic bridging group having at least two carbon atoms in the bridge, and
d) a compound chosen from the group formed by organic nitrites and nitro-compounds.
1.新型催化剂组合物,包括
a)
钯化合物、
b) pKa 小于 6 的酸阴离子、
c) 通式为 R₁R₂M-R-MR₃R₄的双叉
配体,其中 M 代表
磷、
砷或
锑,R₁、R₂、R₃ 和 R₄ 代表可能被或可能不被极性基团取代的烃基,R 是桥中至少有两个碳原子的二价有机桥基,以及
d) 选自有机
亚硝酸盐和
硝基化合物组的化合物。