1,3-Dipolar cycloaddition for selective synthesis of functionalized spiro[indoline-3,3′-pyrrolizines]

• Published in: Chinese chemical letters Vol. 31; no. 6; pp. 1554 - 1557
• Main Authors: Zhu, Meijun, Han, Ying, Liu, Changzhou, Ma, Weiqing, Yan, Chao-Guo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2020; Jianghai Polytechnic College, Yangzhou 225101, China%College of Chemistry&Chemical Engineering, Yangzhou University, Yangzhou 225002, China
• Subjects: 1,3-Dipolar cycloaddition reaction; Azomethine ylide; Electron-deficient alkyne; l-Proline; Spirooxindoline; Spirooxindoline; 1,3-Dipolar cycloaddition reaction; l-Proline; Azomethine ylide; Electron-deficient alkyne; L-Proline
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2019.12.028

The 1,3-dipolar cycloaddition reaction of dimethyl hex-2-en-4-ynedioate with in situ generated azomethine ylides derived from reaction of l-proline and isatins in methanol resulted in functionalized tetrahydrospiro[indoline-3,3′-pyrrolizine]-acrylates as main products and hexahydrospiro[indoline-3,3′-pyrrolizine]propiolates as minor products. [Display omitted] The 1,3-dipolar cycloaddition reaction of dimethyl hex-2-en-4-ynedioate with azomethine ylides derived from reaction of l-proline with various isatins in methanol selectively resulted in the formation of functionalized spiro[indoline-3,3′-pyrrolizine]acrylates as main products and spiro[indoline-3,3′-pyrrolizine]propiolates as minor products. This result indicated that the electron-deficient alkyne has higher reactivity than that of electron-deficient alkene in 1,3-dipolar cycloaddition reaction.