Deformylative Intramolecular Hydroarylation: Synthesis of Benzo[e]pyrido[1,2‑a]indoles

Attempted cyclization of indolizines bearing both formyl and alkyne groups under acid catalysis provided benzo­[e]­pyrido­[1,2-a]­indoles with an aryl substituent at the C6 position as major products, along with the expected C5-acylated benzo­[e]­pyrido­[1,2-a]­indoles as minor ones, which resulted from preferential deformylative intramolecular hydroarylation instead of intended alkyne-carbonyl metathesis.对同时携带甲酰基与炔基的吲哚嗪（indolizines）在酸催化条件下进行环化反应尝试时，主要产物为C6位带有芳基取代基的苯并[e]吡啶并[1,2-a]吲哚嗪（benzo[e]pyrido[1,2-a]indoles），次要产物则为预期的C5-酰化苯并[e]吡啶并[1,2-a]吲哚嗪；该结果源于反应优先发生脱甲酰基分子内氢芳基化，而非预设的炔基-羰基复分解反应。