The reactions of [Pd(η2-dmfu)(PâN)]
 [dmfu = dimethyl fumarate; PâN = 2-(PPh2)C6H4-1-CHNR, R = C6H4OMe-4 (1a), CHMe2
 (2a)] and [Pd(η2-dmfu)(PâN)2] with IC6H4CF3-4, ISnBu3 and PhCCSnBu3 have been studied under pseudo-first-order conditions. The oxidative addition of IC6H4CF3-4 yields [PdI(C6H4CF3-4)(PâN)]
 (1b or 2b). No reaction takes place with PhCCSnBu3 and also with ISnBu3 in the presence of an excess of PhCCSnBu3. In the presence of fumaronitrile (fn), 1b and 2b undergo transmetalation by PhCCSnBu3 followed by fast reductive elimination to yield [Pd(η2-fn)(PâN)]. The same reaction sequence occurs for the system [PdI(C6H4CF3-4)(PâN)]/PâN (1 â¶ 1 molar ratio) to give [Pd(η2-fn)(PâN)2]. The palladium(0) complexes are active catalysts in the cross-coupling of PhCCSnBu3 with aryl iodides ArI (Ar = C6H4CF3-4, Ph). The catalytic efficiency depends on the complex: [Pd(η2-dmfu)(PâN)2] > [Pd(η2-dmfu)(PâN)], and on the substituent R: C6H4OMe-4 > CHMe2. The reactivity and spectroscopic data suggest a catalytic cycle involving initial oxidative addition of ArI to a palladium(0) species, followed by transmetalation of the product and by fast reductive elimination to regenerate the starting palladium(0) compound. For [Pd(η2-dmfu)(PâN)] as catalyst, the oxidative addition is the rate-determining step, while for [Pd(η2-dmfu)(PâN)2] the oxidative addition and the transmetalation steps occur at comparable rate.
                                    在伪一阶条件下研究了[Pd(δ-2-dmfu)(PâN)][dmfu = 
富马酸二甲酯;PâN = 2-(PPh2)
C6H4-1-CHNR, R =     OMe-4 (1a), CHMe2 (2a)] 和[Pd(δ-2-dmfu)(PâN)2]与 I    CF3-4、ISnBu3 和 PhCCSnBu3 的反应。I    CF3-4 的氧化加成反应生成了[PdI(    CF3-4)(PâN)](1b 或 2b)。与 PhCCSnBu3 不发生反应,与 ISnBu3 在过量 PhCCSnBu3 的存在下也不发生反应。在
富马腈(fn)存在的情况下,1b 和 2b 通过 PhCCSnBu3 发生反
金属反应,然后快速还原消除,生成 [Pd(δ-2-fn)(PâN)]。同样的反应顺序也发生在[PdI(    CF3-4)(PâN)]/PâN(1â¶ 1 摩尔比)体系中,生成[Pd(δ-2-fn)(PâN)2]。
钯(0)配合物是 PhCCSnBu3 与芳基
碘化物 ArI(Ar =     CF3-4,Ph)发生交叉偶联反应的活性催化剂。催化效率取决于配合物:[Pd(δ-2-dmfu)(PâN)2] > [Pd(δ-2-dmfu)(PâN)],以及取代基 R:    OMe-4 > CHMe2。反应活性和光谱数据表明,催化循环涉及 ArI 与
钯(0)物种的初始氧化加成,然后是产物的反
金属化和快速还原消除以再生起始
钯(0)化合物。对于作为催化剂的[Pd(δ-2-dmfu)(PâN)]来说,氧化加成是决定速率的步骤,而对于[Pd(δ-2-dmfu)(PâN)2]来说,氧化加成和脱
金属步骤的速率相当。