Overview of 6π 1,5-Electrocyclization over the Past 40 Years

Zhiqiang Huang, Wei Liu, and Wen-Xiong Zhang*

Chin. J. Chem. 2023, 40, 725–740. 

https://doi.org/10.1002/cjoc.202200583 (Invited Critical Review )

      As an important part of pericyclic reaction, 6p 1,5-electrocyclization plays an important role in organic synthesis and chemical theory. Many types of five-membered rings could be constructed via 1,5-electrocyclization with high atom economy. Some elegant works have been reported in this field in the past few decades. However, it still needs a lot of effort in further advancements of 1,5-electrocyclization. This review summarized the development of 1,5-electrocyclization relying on stepwise, stoichiometric, or catalytic approaches. The 1,5-electrocyclization reaction will be divided into three categories: aza 1,5-electrocyclization, all-carbon 1,5-electrocyclization and other heteroatoms (O, P, S) involved 1,5-electrocyclization, and related mechanistic studies will also be involved in this review.