[4 + 1] annulation reaction of cyclic pyridinium ylides with in situ generated azoalkenes for the construction of spirocyclic skeletons. Issue 10 (27th February 2020)

• Record Type: Journal Article
• Authors: Quan, Bao-Xue; Zhuo, Jun-Rui; Zhao, Jian-Qiang; Zhang, Ming-Liang; Zhou, Ming-Qiang; Zhang, Xiao-Mei; Yuan, Wei-Cheng
• Is Part Of: Organic & biomolecular chemistry. Volume 18:Issue 10(2020)
• Page Start: 1886
• Page End: 1891
• Publication Date: 2020-02-27
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c9ob02733e
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Two new kinds of cyclic pyridinium ylides have been firstly designed and used in reactions with in situ generated azoalkenes to access spirocyclic compounds via a [4 + 1] annulation process. Abstract : Two new types of cyclic pyridinium ylides were designed and further used in reactions with azoalkenes to access structurally diverse spirocyclic compounds. A range of spiropyrazoline oxindoles could be smoothly obtained in up to 99% yield via a [4 + 1] annulation process with oxindole 3-pyridinium ylides as C1 synthons. Similarly, a series of spiropyrazoline indanones could be prepared with indanone 2-pyridinium ylides as C1 synthons. This work represents the first example of cyclic pyridinium ylides as C1 synthons for the efficient construction of spirocyclic compounds.