Single-Crystal X-Ray Structure of the Metastable Aryne Precursor Tetrafluorophenyilithium and of 1,2,3,4-Tetrafluorobenzene

摘要

The development of a dehydrobenzene concept can be traced back to the studies of the reaction of phenyllithium with fluoro-benzene performed by Wittig in 1942. The existence of ben-zyne (1,2-didehydrobenzene) and related arynes as intermediates was later established by Roberts, Huisgen, and Wittig. Ever since, dehydrobenzene chemistry has played a major part in many laboratories and is well-documented by numerous review articles. The formation of arynes generally involves the beta-elimination of appropriately positioned sub-stituents from an aromatic precursor Suitable synthetic methods are the fragmentation of benzo-fused cyclic systems, the elimination of nitrogen and carbon dioxide from benzene-diazonium car boxylates or related-compounds, and the elimination of halide ions from "aryl anion" intermediates.