Electrophilic d<sup>0</sup> Cations of Group 4 Metals (M = Ti, Zr, Hf) Derived from Monopentafulvene Complexes: Direct Formation of Tridentate <i>Cp</i>,<i>O</i>,<i>P</i>-Ligands
作者:Malte Fischer、Raoul Schaper、Maximilian Jaugstetter、Marc Schmidtmann、Rüdiger Beckhaus
DOI:10.1021/acs.organomet.8b00088
日期:2018.4.9
chloride/methyl exchange reaction and subsequent reaction with B(C6F5)3 was envisaged to yield the corresponding cationic complexes. Instead, the methylation reactions of Ti2a and Ti2b with methyllithium or methylmagnesium bromide selectively yielded the doubly methylated titanium complexes Ti3a and Ti3b with abstraction of LiCl and the lithium salt of the bidentate P,O-ligand. To avoid this reaction, the P,O-ligand
所述monopentafulvene的反应复合物必须由TI1A和Ti1b与通式的[Cp *的Ti(Cl)的(π-η 5:σ-η 1 -C 5 ħ 4 = CR 2)](R = p -甲苯基(必须由TI1A);据报道,CR 2 =金刚烷(Ti1b),具有二齿P,O-配体前体L1具有二苯基膦和羟基官能团,产生相应的配合物Ti2a和Ti2b去质子化的结果,收率很高。设想氯化物/甲基交换反应以及随后与B(C 6 F 5)3的反应以产生相应的阳离子络合物。取而代之的是,Ti2a和Ti2b与甲基锂或甲基溴化镁的甲基化反应选择性地产生了双甲基化的钛络合物Ti3a和Ti3b,并提取了LiCl和二齿P,O-配体的锂盐。为避免该反应,P,O-配体前体L2制备了以羰基代替羟基官能团为特征的化合物。一般反应顺序的这种变化允许制备新的阳离子钛络合物系列Ti6a和Ti6b,并被转移到较重的同族元素锆(Zr4)和ha(