Chlorotrimethylsilane → 2,2'-Dilithiobiphenyl
Reaction equation
[C-]1[C:14]2[C:5](=C[C:7]3[C:12]([CH:13]=2)=[CH:11][CH:10]=[CH:9][CH:8]=3)[CH:4]=[CH:3][CH:2]=1.[Li+:15].[I-].[Ca+2].[I-].[Ca].Cl[Si](C)(C)C>>[C:12]1([C:13]2[CH:2]=[CH:3][CH:4]=[CH:5][C-:14]=2)[CH:11]=[CH:10][CH:9]=[CH:8][C-:7]=1.[Li+:15].[Li+:15]Participants
5
Procedure
Preformed lithium anthracenide was reacted with calcium iodide to prepare a soluble calcium species. This calcium species was added to chloromethylated polystyrene (DF=0.11) and stirred for 24 hours at room temperature. The corresponding calcium-substituted reagent was then reacted with chlorotrimethylsilane at room temperature to yield the silylated product; however, the yield was not optimized and was lower than the yield obtained from preformed lithium biphenylide (Table III, entry 4). Reaction of the calcium species with chloromethylated polystyrene at 0° C. for 6 hours resulted in a 100% loss of chlorine from the polymer. Subsequent reaction with benzaldehyde gave the corresponding secondary alcohol in 80% yield, compared to the 100% yield when calcium biphenylide was used (Table III, entry 6).