An efficient catalytic system involving in situ activation of kinetically inert titanocene dichloride with alcoholic solvent for the synthesis of quinazoline derivatives was developed. 1 mol% Cp2TiCl2 at 30 °C afforded 17 examples of quinazoline derivatives with yields of 95–98% in 7–12 minutes. Mechanistic experiments using in situ NMR and HRMS established that the coordination of ethanol to the titanocene
开发了一种有效的催化系统,该系统涉及用醇性溶剂原位活化动力学惰性的二
氯化二茂
钛,以合成
喹唑啉衍
生物。在30°C时1 mol%Cp 2 TiCl 2提供了17个实例的
喹唑啉衍
生物,在7-12分钟内产率为95-98%。使用原位NMR和HRMS的机理实验确定,
乙醇与二茂
钛部分的配位释放了催化物质[Cp 2 Ti(OCH 2 CH 3)2 ]。