Diisopropyl-1,10-phenanthroline

The iridium complex [lr(OMe)(cod)2] with 4,4 -di-tert-butyl-2,2 -bipyridine (dtbpy) or 2,9-diisopropyl-l,10-phenanthroline (dipphen) as ligand shows a catalytic activity for aromatic C—H silylation of aromatic compounds by disilane [60]. The reac-hon of 1,2-dimethylbenzene 135 with l,2-di-tert-butyl-l,l,2,2,-tetrafluorodisilane... 

Sodium hydride (0.8 g) was added to 50 ml THE and diethylmalonate added over 5 minutes. l-Bromo-2,4-dimethoxybenzene (1.08 g) was then added in one portion and the reaction flask cooled to — 20°C. A few crystals of 1,10-phenanthroline were added as an indicator and the flask further cooled to —60°C. A few drops of n-BuLi were added until the brown color of the indicator persisted. Thereafter n-BuLi (3.05 mmol) and 0.91ml diisopropylamine was added to form lithium diisopropyl-amide. In order to observe a product conversion of 97%, a total of 2.5 ml EDA added drop wise via cannula in 24 minutes at —20°C to —24°C. The solution was acidified using 1.0 M HCl and the organic portion isolated, washed with brine and isolated in 93.2% purity as a yellow oil. H-NMR data supplied. 

Further non-specific inhibitors include the heavy metal ions Cu ", Fe ", and Hg " (Nees et al 1976) as well as p-chloromercuribenzoate, diisopropyl-fluorophosphate and o-phenanthroline (Schauer and Wember 1971). 

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