Cycloaddition reactions of pyridinium and related azomethine ylides

Stereoselective Synthesis of Tetrahydroindolizines through the Catalytic Formation of Pyridinium Ylides from Diazo Compounds

“…[21,22] The generation of pyridinium ylides in this way has received surprisingly little attention; in fact, we could find only a single example of this type of catalysed three component reaction to form an indolizine. [23] Scheme 2. Synthesis of pyridinium ylides and use for indolizidine synthesis.…”

“…[21,22] The generation of pyridinium ylides in this way has received surprisingly little attention; in fact, we could find only a single example of this type of catalysed three component reaction to form an indolizine. [23] Herein, we describe a new, multicomponent reaction that produces highly functionalized tetrahydroindolizidines in good yields with generally excellent diastereoselectivities (Scheme 2). These reactions involve catalytic generation of pyridinium ylides via metallocarbenes and in situ cycloaddition with electrophilic alkenes.…”

Synthesis and characterization of a substituted indolizine and investigation of its photoluminescence quenching via electron deficient nitroaromatics

“…1 Indolizine derivatives are particularly interesting as they are well known for exhibiting a variety of pharmacologically desirable properties, including cardiovascular, anti-inflammatory and antioxidant properties, 2 as well as having known fluorescent properties and being used in sensor application. [3][4][5] Indolizine derivatives bearing β-cyclodextrin groups have mostly been used for the detection of organic volatile compounds including phenol, p-cresol, 1-adamantanol and 1-adamantonoic acid due to the inclusion…”

One-pot Synthesis of 3-Aryl-substituted 1-Hydroxy-2-acylindolizines

“…ii) The choice of substituents at the N-methylide moieties of the pyridinium ion is narrowed to acyl groups [24] or hydrogen [25] and, hence, affects position 3 of the indolizine. iii) Furthermore, the applied oxidant when using olefines may cause lower yields of the desired products [26].…”