Switching the reactivity of cyanomethylpyridinium salts in the 1,3-cycloaddition conditions with alkyl propiolates to cyanoindolizines or cyanoazaindolizinyl-indolizines

Indolizines and Their Hetero/Benzo Derivatives in Reactions of [8+2] Cycloaddition

“…Another example of cyclazine 54b synthesis from pyridine 54a with ethyl propiolate via indolizine 54c [ 74 ] is illustrated in Scheme 28 . Indolizine 54c could be isolated.…”

1,3-Dipolar cycloaddition of cycloimmonium salts and 4-(trimethylsilyl)-3-butyn-2-one to access new functionalized indolizines with potential cytostatic activity

“…Acetylindolizines were recently revealed to be promising antitumor compounds by effectively targeting farnesyltransferase and/or tubulin polymerization. 1 The influence of the position of the acetyl group was not investigated and, to enrich the structure-activity relationships in this series of compounds and as a continuity of previous studies, 1–4 a series of 1-acetylindolizines were targeted in this study. The synthetic strategy involved a [3+2] cycloaddition reaction which was preferred in terms of atom economy.…”