Construction of pyrazole fused spiroketals by a (3 + 2) annulation reaction. Issue 19 (22nd August 2022)

• Record Type: Journal Article
• Authors: Zhang, Wande; Wei, Xingfu; Wang, Yue; Huang, Yue; Nawaz, Shah; Qu, Jingping; Wang, Baomin
• Is Part Of: Organic chemistry frontiers. Volume 9:Issue 19(2022)
• Page Start: 5197
• Page End: 5204
• Publication Date: 2022-08-22
• Subjects: Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1039/d2qo01001a
• Languages: English
• ISSNs: 2052-4110

Abstract

Abstract : A stereoselective (3 + 2) annulation process between 4-bromo pyrazolones and benzofuran-derived azadienes was developed. A series of novel pyrazole fused spiroketals were synthesized in the presence of triethylamine. Abstract : A stereoselective (3 + 2) annulation process between 4-bromo pyrazolones and benzofuran-derived azadienes was developed. A series of novel pyrazole fused spiroketals were synthesized in the presence of a base. The process has the salient features of simple operation, mild conditions, and fast reaction rate. The asymmetric (3 + 2) annulation reaction was initially explored, and an optimal catalytic system was obtained. The applicability of a few substrates was investigated, highlighting the possibility of asymmetric catalytic synthesis of chiral pyrazole fused spiroketals.