Assignment of E–Z-configurations of spiro-oxirane-oxindoles synthesized by rhodium(II) acetate-catalyzed reaction of ethyl diazoacetate with N-methylisatin. Issue 3 (15th March 2016)

• Record Type: Journal Article
• Authors: Ngaski, Abubakar M.; Singh, Girija S.
• Is Part Of: Spectroscopy letters. Volume 49:Issue 3(2016)
• Page Start: 214
• Page End: 216
• Publication Date: 2016-03-15
• Subjects: 1, 3-dioxolane -- α-diazocarbonyls -- isatin -- NOESY -- spiro-oxirane; Spectrum analysis -- Periodicals; 543.5
• DOI: 10.1080/00387010.2015.1121499
• Languages: English
• ISSNs: 0038-7010

Abstract

ABSTRACT: The rhodium(II) acetate [Rh2 (OAc4 )]-catalyzed reaction of ethyl diazoacetate with N -methylisatin leads to the formation of diastereomeric oxiranes spiro-fused to N -methyl-2-oxindole together with 1, 3-dioxolane bis-spiro-fused to N -methyl-2-oxindole. The formation of ylide from the reaction of rhodium-carbenoid with C-3 carbonyl group of the N -methylisatin undergoing a 1, 3-cyclization, and a [3 + 2]-dipolar cycloaddition with another molecule of N- methylisatin, respectively, explains the formation of products. The application of nuclear overhauser effect spectroscopy to determine the E – Z -configurations of the spiro-oxirane-oxindoles is demonstrated.