Synthesis of Spiropyrrolizidine via 1,3-dipolar cycloaddition reaction from E-arylidene-succinimides adduct obtain by in situ Wittig reaction

Three-component reactions are characterized as convergent synthesis, because the three reagents lead to a product which contains most of all atoms of the reagents1. Arylidene-succinimides are system which present the C=C-C=O electrophilic moiety, susceptible to the 1,3-dipolar cycloaddition reaction2. Wittig reaction is the most of important reaction that promote olefination3. Therefore, to access a set of arylidene-succinimides4,5 we describe herein a three-component reaction of N-substituted maleimides 1(a-f), aldehydes 2(a-e) and triphenylphosphine 3 in methanol at room temperate to obtain E-arylidene-succinimides isomer as major isomer, Scheme 1. Fortunately, the purification process was simple because the products precipitated. A representative set of derivatives could be obtained in reasonable yield and reaction time. We investigated the reactivity of 4k through one-pot reaction of isatin with proline to obtain Spiropyrrolizidine. The product was obtained by chromatographic column in moderate yield. Therefore, we investigated the three-component synthesis of arylidene-succinimides and has developed 1,3-dipolar cycloaddition reaction.