Synthesis of π‑Extended Fluoranthenes via a KHMDS-Promoted Anionic-Radical Reaction Cascade

An unprecedented KHMDS-promoted domino reaction to furnish hydroxyfluoranthenes is described. Biaryl compounds bearing acyl and naphthylalkenyl moieties are transformed into 9-hydroxydibenzo­[j,l]­fluoranthenes in a single step through the formation of an aromatic and a pentagonal ring system. A variety of fluoranthenes including those with extended π-conjugation, a heteroaromatic ring, and unsymmetrical substituents could be synthesized. Mechanistic studies reveal a unique reaction cascade where KHMDS acts as both a base and a single-electron donor.本文报道了一种前所未有的、由六甲基二硅基胺基钾（KHMDS）介导的串联反应，用于制备羟基荧蒽类化合物。带有酰基与萘基烯基基团的联芳基化合物，可通过一步构建芳香环与五元环的过程，转化为9-羟基二苯并[j,l]荧蒽。该策略可合成多种荧蒽类衍生物，涵盖具有拓展π共轭体系、杂芳环以及不对称取代基的荧蒽结构。机理研究揭示了一种独特的反应级联过程，其中KHMDS同时充当碱与单电子给体。