Selective metallation of 3-halothiophenes: Practical methods for the synthesis of 2-bromo-3-formylthiophene
Selective lithiation of 3-bromothiophene was accomplished under controlled conditions without formation of undesired thienyllithium compounds. A thienyl Grignard reagent derived from 2-bromo-3-iodothiophene was transformed into 2-bromo-3-formylthiophene in high selectivity by formylation with dimethylformamide (DMF) at optimal reaction temperature. Copyright Taylor & Francis Group, LLC.