Palladium-Catalyzed Aerobic Oxidative Coupling of <i>ortho</i>-(Alkynyl)styrenes with Allylic Alcohols via 6-<i>endo-dig</i> Cyclization: Regioselective Construction of Polysubstituted Naphthalenes

An efficient protocol is described for the regioselective construction of polysubstituted functionalized naphthalenes from easily accessible ortho-(alkynyl)­styrenes under mild reaction conditions. The reaction proceeds via cycloaromatization and intermolecular coupling of ortho-(alkynyl)­styrenes with allylic alcohols catalyzed by PdCl2. Notably, the reaction is successful under open air as the green oxidant source. A range of functional groups (F, Cl, Br, NO2, and ester) including protecting free OH groups were found to be compatible.本研究报道了一种高效的区域选择性合成策略，可在温和反应条件下，由易于获取的邻(炔基)苯乙烯（ortho-(alkynyl)styrenes）制备多取代官能化萘。该反应以PdCl₂为催化剂，通过邻(炔基)苯乙烯与烯丙醇的环芳构化及分子间偶联过程进行。值得注意的是，该反应可在敞口空气环境中进行，以空气作为绿色氧化剂源。实验结果表明，包括未保护的游离羟基在内的多种官能团（氟、氯、溴、硝基与酯基）均具有良好的兼容性。