Regioselective Orthopalladation of (<i>Z</i>)-2-Aryl-4-Arylidene-5(4<i>H</i>)-Oxazolones: Scope, Kinetico-Mechanistic, and Density Functional Theory Studies of the C–H Bond Activation
作者:Gheorghe-Doru Roiban、Elena Serrano、Tatiana Soler、Gabriel Aullón、Ion Grosu、Carlos Cativiela、Manuel Martínez、Esteban P. Urriolabeitia
DOI:10.1021/ic200564d
日期:2011.9.5
of the six-membered ring is shown to be favored from both a kinetic and a thermodynamic perspective. In addition, the dependence of the reaction rate on the acidity of the medium has also been accounted for via a fine-tuning between the C–H agostic precoordination and the proton abstraction reaction in the overall process occurring on coordinatively saturated [Pd(κN-oxazolone)(RCO2H)3]2+.
通过使恶唑酮与乙酸钯在酸性介质中反应,已经制备了由(Z)-2-芳基-4-芳基亚芳基-5(4H)-恶唑酮衍生的邻钯配合物。该反应是区域选择性的,只有亚芳基环的邻位CH键被激活,产生一个六元环。正钯的范围和反应条件取决于溶剂的酸度。在CF 3 CO 2中在温和的条件下,大量的恶唑酮可被金属化。随着酸度的降低,可以有效地降低较少的恶唑酮的使用量,必须使用更苛刻的条件才能获得相似的收率。酸性介质中的C–H键活化与歧义机理相吻合,这是通过在可变温度和压力下对在亚芳基环上取代的不同恶唑酮的动力学测量确定的。该机理已通过密度泛函理论(DFT)计算得到证实,从动力学和热力学角度来看,六元环的形成均被证明是有利的。此外,N-恶唑酮)(RCO 2 H)3 ] 2+。
Fluorophores related to the green fluorescent protein
Imidazolin-5-one derivatives and isosteres (oxazolinones, butenolides, and pyrrolinones) of the 4-hydroxybenzylideneim-idazolinone chromophore of the GFP have been synthesized and their photophysical properties have been investigated. (C) 2004 Elsevier Ltd. All rights reserved.
Nakajima, Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan, 1956, vol. 76, p. 1008
作者:Nakajima
DOI:——
日期:——
Unexpected [2 + 2] C–C bond coupling due to photocycloaddition on orthopalladated (Z)-2-aryl-4-arylidene-5(4H)-oxazolones
作者:Doru Roiban、Elena Serrano、Tatiana Soler、Ion Grosu、Carlos Cativiela、Esteban P. Urriolabeitia
DOI:10.1039/b907647f
日期:——
A [2 + 2] photocycloaddition has been observed in regioselectively orthopalladated 2-aryl-4-arylidene-5(4H)-oxazolones, leading to unprecedented cyclobutane-bis(oxazolones).