Polymer supported magnesium anthracene: application in the synthesis of benzylic Grignard reagents

Reactions of polystyrene supported magnesium anthracene containing radical anion and dianion sites, 7, 7′, with benzylic chlorides or bromides, affords Grignard reagents, RMgX, in modest to high yields, in THF at -10°C to 20°C. Novel benzylic-type Grignard reagents prepared in high yield include those of 2,6-(dichloromethyl)pyridine, 2,6-(dibromomethyl)pyridine, 2,2′2″-trispyridylmethylchloride, 2-methoxy-3-methyl-1-benzychloride, 2,4-dimethoxy-5-methyl-1-benzylchloride, 3,5-dimethoxy-4-benzylchloride, 2,4,6-trimethoxy-3-methyl-1-benzylchloride, and 2,5-dimethoxybenzylchloride. Selected allylic halides similarly yield Grignard reagents.