[4+n] Annulation Reactions Using ortho-Chloromethyl Anilines as Aza-ortho-Quinone Methide Precursors

作者：He, Xiao-Yu; Ma, Yu-Hong; Yang, Qing-Qing^*; Xiao, Wen-Jing^*

来源：Synthesis, 2022, 54(04): 953-964.

DOI：10.1055/a-1529-7739

• annulation
• nitrogen-containing heterocycles
• aza-ortho-quinone methides
• ortho-chloromethyl anilines
• 4-atom units

Aza-ortho-quinone methides are important reactive intermediates that have found broad applications in synthetic chemistry. Recently, 1,4-elimination of ortho-chloromethyl aniline derivatives has emerged as a novel, powerful and convenient method for aza-ortho-quinone methide generation. This review will highlight the recent applications of aza-ortho-quinone methide precursors in annulation reactions to access various biologically important nitrogen-containing heterocycles. The general mechanisms are briefly discussed as well. @@@ 1 Introduction @@@ 2 [4+n] Annulation Reactions Using ortho-Chloromethyl Anilines as Aza-ortho-Quinone Methide Precursors @@@ 2.1 [4+2] Annulation Reactions @@@ 2.2 [4+1] Annulation Reactions @@@ 2.3 [4+3] Annulation Reactions @@@ 3 Conclusion and Perspective