Group 4 Diarylmetallocenes as Bespoke Aryne Precursors for Titanium-Catalyzed [2 + 2 + 2] Cycloaddition of Arynes and Alkynes
作者:Benjamin R. Reiner、Ian A. Tonks
DOI:10.1021/acs.inorgchem.9b01082
日期:2019.8.19
reports describing titanium (Ti)-catalyzed [2 + 2 + 2] cyclotrimerization of alkynes, the incorporation of arynes into this potent manifold has never been reported. The in situ generation of arynes often requires fluoride, which instead will react with the highly fluorophilic Ti center, suppressing productive catalysis. Herein, we describe the use of group 4 diarylmetallocenes, CpR2MAr2 (CpR = C5H5,
尽管有大量报道描述了钛(Ti)催化炔烃的[2 + 2 + 2]环三聚反应,但从未报道过将芳烃掺入到这种有效的歧管中。芳烃的原位生成通常需要氟化物,而氟化物将与高度氟的Ti中心反应,从而抑制生产催化。在这里,我们描述了使用第4组二芳基金属茂CpR2MAr2(CpR = C5H5,C5Me5; M = Ti,Zr)作为芳烃前体,通过与2当量的炔烃偶合,进行Ti催化的取代萘的合成。催化剂负载量为1%时,可获得所需萘产品的中等至良好收率,这比钯或镍催化的类似反应低约一个数量级。此外,萘在电子产品,光伏产品,和制药业,敦促发现更多的经济综合体。这些结果表明,芳烃从CpR2M(η2-芳烃)配合物转移到另一种金属是将芳烃片段引入有机金属催化过程的可行途径。