suggest that the reaction using a compact and basic mono-phosphorus complex proceeds by the Chalk–Harrod mechanism involving the reductive elimination from an (η3-allyl)(silyl)palladium(II). A poor electron-donating mono-phosphorus ligand such as P(OPh)3 destabilizes a Pd(II) species and promotes direct reductive elimination to give the 1,4-Z product. On the other hand, a compact and electron-donating phosphorus
单(膦)
钯(0)配合物,[将Pd(η 2:η 2 -C 6 ħ 10 O)(PR 3)](1),与催化HSiPh缺电子共轭二烯的氢化
硅烷化3。甲基戊-2,4-二烯酸酯的氢化
硅烷化与HSiPh 3通过[加入Pd(η催化2:η 2 -C 6 ħ 10 O)(PR 3)](R =我(1A),的Et(1B),OET(1d),O i Pr(1e))继续得到1,2- E产品具有独特的马尔可夫尼可夫选择性的定量收率。与此相反,它们的
三苯基膦和
亚磷酸酯类似物,[将Pd(η 2:η 2 -C 6 ħ 10 O)(PR 3)](R = Ph(上1F),OPH(1克)),主要产生1,4- - ž产物(1,2- é / 1,4- ž = 3/7)。
2,4-戊二烯酸甲酯的
硅氢加成反应中的区域选择性也受有机
硅烷控制。机理研究表明,使用反应通过涉及从还原消除粉笔-哈罗德机构紧凑且基本单-
磷配合物进入(η 3-烯丙基)(