Bond Activation, Substrate Addition and Catalysis by an Isolable Two-Coordinate Pd(0) Bis-Isocyanide Monomer,Journal of the American Chemical Society

当前位置： X-MOL 学术 › J. Am. Chem. Soc. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Bond Activation, Substrate Addition and Catalysis by an Isolable Two-Coordinate Pd(0) Bis-Isocyanide Monomer
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2009-08-19 , DOI: 10.1021/ja905338x
Liezel A. Labios ₁ , Matthew D. Millard ₁ , Arnold L. Rheingold ₁ , Joshua S. Figueroa ₁

Affiliation

Mg metal reduction of the divalent precursor PdCl(2)(CNAr(Dipp2))(2) (Dipp = 2,6-diisopropylphenyl) provides the isolable, two-coordinate Pd(0) bis-isocyanide, Pd(CNAr(Dipp2))(2), which is the first stable monomeric isocyanide complex of zerovalent palladium. Variable temperature (1)H NMR and FTIR studies on Pd(CNAr(Dipp2))(2) in the presence of added CNAr(Dipp2) revealed that free and coordinated isocyanide undergo rapid exchange, but the components do not form a stable tris-isocyanide complex. Bis-isocyanide Pd(CNAr(Dipp2))(2) is active for oxidative addition reactions and readily reacts with benzyl chloride and mesityl bromide to form Pd(Cl)(Bz)(CNAr(Dipp2))(2) and Pd(Br)(Mes)(CNAr(Dipp2))(2), respectively. Room-temperature Suzuki-Miyaura cross-coupling reactions are mediated by Pd(CNAr(Dipp2))(2). Coordinatively and electronically unsaturated substrates also react with Pd(CNAr(Dipp2))(2). Addition of thallium(I) triflate (TlOTf) to Pd(CNAr(Dipp2))(2) results in the salt [TlPd(CNAr(Dipp2))(2)]OTf, while addition of O(2) results in the peroxo complex (eta(2)-O)Pd(CNAr(Dipp2))(2). Most remarkably, 2 equiv of nitrosobenzene react with Pd(CNAr(Dipp2))(2) to form the square planar complex (kappa(1)-N-PhNO)(2) Pd(CNAr(Dipp2))(2), the geometry of which strongly suggests the formation of a divalent Pd center. With the aid of density functional theory calculations, this valence change is rationalized in terms of a formal reduction of the bond order in each NO unit to 1.5.

中文翻译：

可分离的双配位 Pd(0) 双异氰化物单体的键活化、底物添加和催化

二价前体 PdCl(2)(CNAr(Dipp2))(2)（Dipp = 2,6-二异丙基苯基）的镁金属还原提供了可分离的双配位 Pd(0) 双异氰化物 Pd(CNAr(Dipp2) )(2)，这是第一个稳定的零价钯单体异氰化物配合物。在添加 CNAr(Dipp2) 的情况下，对 Pd(CNAr(Dipp2))(2) 的变温 (1)H NMR 和 FTIR 研究表明，游离的和配位的异氰化物会发生快速交换，但组分不会形成稳定的三异氰化物络合物。双异氰化物 Pd(CNAr(Dipp2))(2) 对氧化加成反应很活跃，很容易与苄基氯和甲基溴反应形成 Pd(Cl)(Bz)(CNAr(Dipp2))(2) 和 Pd(Br )(Mes)(CNAr(Dipp2))(2)。室温 Suzuki-Miyaura 交叉偶联反应由 Pd(CNAr(Dipp2))(2) 介导。配位和电子不饱和底物也会与 Pd(CNAr(Dipp2))(2) 反应。将铊 (I) 三氟甲磺酸 (TlOTf) 添加到 Pd(CNAr(Dipp2))(2) 产生盐 [TlPd(CNAr(Dipp2))(2)]OTf，而添加 O(2) 产生过氧络合物 (eta(2)-O)Pd(CNAr(Dipp2))(2)。最值得注意的是，2 当量的亚硝基苯与 Pd(CNAr(Dipp2))(2) 反应形成方形平面络合物 (kappa(1)-N-PhNO)(2) Pd(CNAr(Dipp2))(2)，其几何形状强烈表明二价 Pd 中心的形成。在密度泛函理论计算的帮助下，这种价态变化可以通过将每个 NO 单元中的键序正式减少到 1.5 来合理化。而添加 O(2) 会产生过氧复合物 (eta(2)-O)Pd(CNAr(Dipp2))(2)。最值得注意的是，2 当量的亚硝基苯与 Pd(CNAr(Dipp2))(2) 反应形成方形平面络合物 (kappa(1)-N-PhNO)(2) Pd(CNAr(Dipp2))(2)，其几何形状强烈表明二价 Pd 中心的形成。在密度泛函理论计算的帮助下，这种价态变化在每个 NO 单元中的键序正式减少到 1.5 方面被合理化。而添加 O(2) 会产生过氧复合物 (eta(2)-O)Pd(CNAr(Dipp2))(2)。最值得注意的是，2 当量的亚硝基苯与 Pd(CNAr(Dipp2))(2) 反应形成方形平面络合物 (kappa(1)-N-PhNO)(2) Pd(CNAr(Dipp2))(2)，其几何形状强烈表明二价 Pd 中心的形成。在密度泛函理论计算的帮助下，这种价态变化在每个 NO 单元中的键序正式减少到 1.5 方面被合理化。

更新日期：2009-08-19

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南