Update on the Synthesis of N‐Heterocycles via Cyclization of Hydrazones (2017–2021). Issue 23 (15th November 2021)

• Record Type: Journal Article
• Authors: Lv, Yunhe; Meng, Jianping; Li, Chen; Wang, Xin; Ye, Yong; Sun, Kai
• Is Part Of: Advanced synthesis & catalysis. Volume 363:Issue 23(2021)
• Page Start: 5235
• Page End: 5265
• Publication Date: 2021-11-15
• Subjects: hydrazones -- N-heterocycles -- catalysis -- cyclization -- mechanisms; Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.202101184
• Languages: English
• ISSNs: 1615-4150

Abstract

Abstract: Hydrazones, as universal structural units, are useful synthons for the formation of carbon–nitrogen and nitrogen−heteroatom bonds. Thus, they provide new methods of constructing nitrogen‐containing heterocycles. In recent years, especially between 2017 and 2021, many efforts have been made to exploit hydrazone‐based reactions in efforts to develop more powerful and effective pathways towards the synthesis of various multifunctional heterocyclic compounds. However, despite the tremendous amount of work that has been published over the past five years, no review has been published that summarizes the significant progress in the preparation of nitrogen heterocycles via intramolecular cyclization of hydrazones with adjacent unsaturated bonds or intermolecular cyclization of hydrazones with unsaturated systems. Therefore, this review summarizes the hydrazone‐based cyclization strategies used to synthesize nitrogen‐containing heterocycles over the past five years. It discusses the corresponding reaction scopes, limitations, mechanisms, and problems. Abstract :