Reactions of trialkyl(2-furyl) germanes with electrophilic reagents

Abstract

The metallation (n-BuLi), alkylation (t-BuOH/H +), nitration (NO 2 + BF 4 −), bromination (NBS, dioxane dibromide (DDB)), acylation [(CF 3CO) 2O] and chlorination (chloramine T) reactions of (2-furyl)germanes were studied. Except for alkylation and bromination with DDB, the reactions involved electrophilic substitution of hydrogen atoms in position 5 or 3 of the furan ring. The alkylation reaction and bromination with DDB occur via ipso-substitution of the trialkylgermyl group. Dichlorocarbene generated by phase-transfer catalysis adds to the 2-germyl-substituted furan at the C 4C 5 bond in the ring. Some of the above reactions were conducted with trimethyl(2-furyl)silane and 2-(t-butyl)furan, the silicon and carbon analogues of furylgermanes. The reactivities of the title compounds were compared.