Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States.
J Am Chem Soc. 2013 Jun 26;135(25):9433-41. doi: 10.1021/ja401390v. Epub 2013 Jun 13.
The synthesis of the Lewis acid-base adducts of B(C6F5)3 and BF3 with [DAAmRe(O)(X)] DAAm = N,N-bis(2-arylaminoethyl)methylamine; aryl = C6F5 (X = Me, 1, COCH3, 2, Cl, 3) as well as their diamidopyridine (DAP) (DAP=(2,6-bis((mesitylamino)methyl)pyridine) analogues, [DAPRe(O)(X)] (X = Me, 4, Cl, 5, I, 6, and COCH3,7), are described. In these complexes the terminal oxo ligands act as nucleophiles. In addition we also show that stoichiometric reactions between 3 and triarylphosphine (PAr3) result in the formation of triarylphosphine oxide (OPAr3). The electronic dependence of this reaction was studied by comparing the rates of oxygen atom transfer for various para-substituted triaryl phosphines in the presence of CO. From these experiments a reaction constant ρ = -0.29 was obtained from the Hammett plot. This suggests that the oxygen atom transfer reaction is consistent with nucleophilic attack of phosphorus on an electrophilic metal oxo. To the best of our knowledge, these are the first examples of mono-oxo d(2) metal complexes in which the oxo ligand exhibits ambiphilic reactivity.
描述了 Lewis 酸碱加合物 B(C6F5)3 和 BF3 与 [DAAmRe(O)(X)]（DAAm = N,N-双(2-芳氨基乙基)甲胺；芳基 = C6F5（X = Me、1、COCH3、2、Cl、3）的合成，以及它们的二酰胺吡啶（DAP）（DAP =（2,6-双((间三甲氨基甲基)吡啶）类似物，[DAPRe(O)(X)]（X = Me、4、Cl、5、I、6 和 COCH3、7）。在这些配合物中，末端的氧配体作为亲核试剂。此外，我们还表明，3 与三芳基膦（PAr3）之间的化学计量反应导致三芳基氧化膦（OPAr3）的形成。通过比较在 CO 存在下各种对位取代的三芳基膦的氧原子转移速率，研究了该反应的电子依赖性。从这些实验中，从哈米特图中得到了一个反应常数 ρ = -0.29。这表明氧原子转移反应与磷对亲电金属氧的亲核攻击一致。据我们所知，这些是第一个展示具有亲核反应性的单氧 d(2)金属配合物的实例。
