Paraja Miguel, Valdés Carlos
Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, c/ Julián Clavería 8, Oviedo, 33006, Spain.
Chem Commun (Camb). 2016 May 7;52(37):6312-5. doi: 10.1039/c6cc01880g. Epub 2016 Apr 18.
Two different Pd-catalyzed cascade reactions between o-iodo-N-alkenylanilines and tosylhydrazones are described. The outcome of the cascade processes is determined by the substitution on the N-alkenyl fragment. The reactions with N-tosyl-N-ethylene-o-iodoanilines lead to indoles through a sequence that involves the sequential migratory insertions of a carbene ligand and a C-C double bond, featuring a 5-exo-trig cyclization. The reactions with N-alkyl-N-alkenyl-o-iodoanilines provide 1,4-dihydroquinolines through a cascade reaction that includes a formal 6-endo-trig cyclization. In both cases the benzofused heterocycles are built through the formation of two C-C bonds on the hydrazonic carbon atom.
本文描述了邻碘-N-烯基苯胺与甲苯磺酰腙之间两种不同的钯催化串联反应。串联反应的结果由N-烯基片段上的取代基决定。N-甲苯磺酰基-N-乙烯基邻碘苯胺的反应通过一系列过程生成吲哚，该过程涉及卡宾配体和碳-碳双键的顺序迁移插入，具有5-外环化特征。N-烷基-N-烯基邻碘苯胺的反应通过包括形式上的6-内环化的串联反应提供1,4-二氢喹啉。在这两种情况下，苯并稠合杂环都是通过在腙碳原子上形成两个碳-碳键而构建的。
