Functionalized Cyclopentadienes: Synthesis of 1,3-Bis(1,1-dimethylbut-3-cyclopentadienyl Systems

摘要

The synthesis of the new cyclopentadiene C_5H_4(CMe_2CH_2CHCH_2)_2 4 is described. The key step of the reaction sequence is the regioselective formation of the 2-(1,1-dimethylbut-3-enyl)-6,6-dimethylfulvene 2. The substitution pattern of 4 can be confirmed by the structure fo the Diels-Alder product obtained from 2 and dimethyl acetylenedicarboxylate. Compound 4 is converted into the corresponding cyclopentadienides 5a,b via metallation with n-BuLi and KH, respectively. Compounds 4 and 5a,b are suitable candidates for the synthesis of functionalized cyclopentadienyl complexes in organometallic chemistry.