REACTIVITY AND MECHANISM IN OXIDATIVE ADDITION TO PALLADIUM(II) AND REDUCTIVE ELIMINATION FROM PALLADIUM(IV) AND AN ESTIMATE OF THE PALLADIUM-METHYL BOND-ENERGY
REACTIVITY AND MECHANISM IN OXIDATIVE ADDITION TO PALLADIUM(II) AND REDUCTIVE ELIMINATION FROM PALLADIUM(IV) AND AN ESTIMATE OF THE PALLADIUM-METHYL BOND-ENERGY
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DOI：
10.1021/om00096a021
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发表时间：
1988-06-01
期刊：
影响因子：
2.8
通讯作者：
SCOTT, JD
中科院分区：
文献类型：
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作者：
BYERS, PK;CANTY, AJ;SCOTT, JD
结果氧化加成反应。[PdMe_2（bpy）]与Mel在CD_3CN中的反应用NMR进行了监测。在-40 ℃下混合试剂，在此温度下观察到两种产物以约3：1的比例产生共振.主要产物[PdIMe 3（bpy）]的共振为1.79（PdMe反式为N）和1.20（PdMe反式至I）;第二个产物被指定为离子[PdMe 3（CD 3CN）（bpy）]+ I-，具有1.61（PdMe反式为bpy）和1.06（PdMe反式至CD 3CN），与涉及三足氮供体配体如[PdMe 3（三（吡啶-2-基）甲烷）] I的孤立阳离子有关。[9]阳离子的甲基共振随温度升高而变宽，在>-5 ℃时发生凝聚，但阳离子的bpy共振和[PdIMe 3（bpy）]的所有共振仍然很尖锐，这与阳离子中甲基增强的分子内交换（混乱）相一致;再冷却到低温时，得到原始光谱，具有相同的积分。在较高温度（> 15 ℃）下，中性和阳离子络合物的bpy共振合并，并且与产物[PdlMe（bpy）]的尖锐的、增长的共振相比，bpy和甲基共振较宽，表明[PdMe 3（bpy）（CD 3CN）]+ T之间的交换。
Results The Oxidative Addition Reaction. Thereaction of [PdMe2 (bpy)] with Mel in CD3CN was monitored byNMR. The reagents were mixed at-40 C, and at this temperature resonances due totwo products in~ 3: 1 ratio were observed. Resonances due to the majorproduct [PdIMe3 (bpy)] were at 1.79 (PdMe trans to N) and 1.20 (PdMe trans to I); the second product was assigned to the ionic [PdMe3 (CD3CN)(bpy)]+ I" with 1.61 (PdMe trans to bpy) and 1.06 (PdMe trans to CD3CN), related to iso-lated cations involving tripodal nitrogen donor ligands such as [PdMe3 (tris (pyridin-2-yl) methane)] I. 9 Methyl group resonances for the cation broaden on warming, with coa-lescence at>-5 C, but bpy resonances for the cation and all resonances for [PdIMe3 (bpy) J remain sharp, consistent with intramolecular exchange (scrambling) of methyl en-vironments in the cation; on recooling to low temperature the original spectrum is obtained, with identicalintegration. At higher temperatures (> 15 C) bpy resonances for the neutral and cationic complexes are coalesced, and the bpy and methyl resonances are broad compared to the sharp, growing resonances for the product [PdlMe (bpy)], indicating exchange between [PdMe3 (bpy)(CD3CN)]+ T