Tautomerization of Pyridine and 2-Substituted Pyridines to Pyridylidene Ligands by the Iridium(I)–Diene Complex Tp<sup>Me2</sup>Ir(η<sup>4</sup>-CH<sub>2</sub>═C(Me)C(Me)═CH<sub>2</sub>)
作者:Florencia Vattier、Verónica Salazar、Margarita Paneque、Manuel L. Poveda、Eleuterio Álvarez
DOI:10.1021/om400968s
日期:2014.1.27
The complex TpMe2Ir(η4-CH2═C(Me)C(Me)═CH2) (3; TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) reacts with pyridines NC5H4-2-R (R = H, Me, SiMe3, F, OMe, NMe2, C(═O)Me) in cyclohexane, with formation of Ir(III) products whose natures depend strongly on the reaction conditions and on the R substituent. The simplest case is for R = NMe2, C(═O)Me, where κ2:σ2-but-2-enediyl N–H pyridylidenes, i.e. the
所述络合物TP ME2的Ir(η 4 -CH 2 = C(Me)的C(Me)的= CH 2)(3 ; TP ME2 =氢三(3,5- - dimethylpyrazolyl)硼酸盐)与吡啶发生反应NC 5 H ^ 4 -2- R(R = H,Me,SiMe 3,F,OMe,NMe 2,C(= O)Me)在环己烷中形成Ir(III)产物,其性质很大程度上取决于反应条件和R取代基。最简单的情况是对于R = NME 2,C(= O)Me,其中κ 2:σ 2从60到150°C的温度下获得的唯一物种是-丁-2-二烯基N-H吡啶基,即吡啶金属催化的互变异构化的结果。对于R = Me中,F中的N-键合的加成物TP ME2的Ir(κ 2 -CH 2 C(Me)的= C(Me)的CH 2)(NC 5 H ^ 4-2-R)是在60°C下形成的,但在更苛刻的条件下(120–150°C),观察到的产物分别是N–H