The synthesis of 1,2-dihydroisoquinoline, [2,1-a] isoquinoline and [5,1-a] isoquinoline is very important because of their biological and medicinal activities as well as their conversion to corresponding isoquinoline. Various nucleophiles and pronucleophiles could be added to Ortho-alkynylbenzaldehydes, ortho-alkynylaryl aldimines and ortho-alkynylbenzaldoximes in the presence of different Lewis acids and generate derivatives of 1,2-dihydroisoquinoline in tandem route. Also, 1,4-dipolar intermediate which synthesized from the reaction of isoquinoline and electron-deficient compounds reacted with various dipolarophiles for the formation of five- and six-membered heterocycles including [2,1-a] isoquinoline and [5,1-a] isoquinoline. In recent years, these interesting zwitterions have been used in multicomponent reactions to produce a considerable number of heterocyclic compounds. In this review, I have classified a variety of methods since 2006 until now, for the generation of 1,2-dihydroisoquinoline, [2,1-a] isoquinoline and [5,1-a] isoquinoline via the above routes.

1,2-二氢异喹啉的合成，[2,1-一个]异喹啉并[5,1-一个]异喹啉是因为它们的生物和药用活性以及它们转化成相应的异喹啉的非常重要的。在不同路易斯酸的存在下，可以将各种亲核试剂和原亲核试剂加入到邻炔基苯甲醛、邻炔基芳基醛亚胺和邻炔基苯甲醛肟中，并以串联方式生成 1,2-二氢异喹啉衍生物。此外，由异喹啉和缺电子化合物反应合成的 1,4-偶极中间体与各种亲偶极体反应形成五元和六元杂环，包括 [2,1- a]异喹啉和[5,1- a ]异喹啉。近年来，这些有趣的两性离子已被用于多组分反应中，以产生大量的杂环化合物。在这篇综述中，我已经分类了多种自2006年以来的方法到现在为止，用于产生1,2-二氢异喹啉的，并[2,1-一个]异喹啉并[5,1-一个]异喹啉通过上述路线。