Facile Regioselective Synthesis of Pyrazolo[5,1-<i>a</i>]isoquinolines via Ring-Opening Cyclization/Oxidation Reactions of Stable Aroyldiaziridines of 3,4-Tetrahydroisoquinoline with Alkynes
作者:Howard Alper、Heriberto Ortega、Sara Ahmed
DOI:10.1055/s-2007-990888
日期:2007.12
4-tetrahydroisoquinolines undergo regioselective cycloaddition reactions with a number of both mono and disubstituted alkynes, affording five-membered ring products which, after oxidative aromatization of the pyrazoline ring, lead to the efficient preparation of pyrazolo[5,1-a]isoquinolines. The overall transformation is base-catalyzed and occurs more rapidly in the presence of oxygen, in halogenated
:: 新制备的稳定的 3,4-四氢异喹啉的芳酰基二氮丙啶与许多单取代和双取代炔烃发生区域选择性环加成反应,得到五元环产物,在吡唑啉环氧化芳构化后,可有效制备吡唑啉[5,1-a]异喹啉。整个转化是碱催化的,在有氧、卤化溶剂和二恶烷的情况下发生得更快。