Reactivity and stereoselectivity of oxazolopyridines with a ring‐junction nitrogen atom

Abstract

The present study demonstrates a synopsis of the scientific researches reported on the different reactions of oxazolo[3,2‐a]pyridines, besides the preparation of significant fused heterocycles up till now. The different main sections that described the reactivity of the inspected analogues include stereoselective alkylation, reactions involved oxazolidine ring, synthesis of polycyclic systems, indole alkaloids, and alkyl amines. The stereochemical selectivity of oxazolopiperidone lactams is studied, in which the configuration of the stereocenter C8a and substituents at the C8 and C8a effect on the stereoselectivity. On the other hand, the synthetic consequence of the alkylation products provides diverse routes for the synthesis of substituted enantiopure piperidines that are used for the synthesis of natural products, for example, (−)‐rhazinilam, (+)‐eburnamonine, (+)‐aspidospermidine, indole alkaloids such as dihydrocleavamine, nor‐20‐epiuleine, (+)‐dasycarpidone, (+)‐uleine, indoloquinolizidine, (+)‐dihydrocorynantheine, (−)‐dihydrocorynantheol, and indolizines, eg, octahydroindolizines, monomorine I, (−)‐S‐coniceine, and (−)‐R‐coniceine.

Synthesis, biological activities, and future perspectives of steroidal monocyclic pyridines

“…27 Our recent work was directed toward the exploration of the chemistry and biological diversity of heterocyclic steroids incorporating pyridine moieties of biological importance 28,29 in addition to the chemistry of heterocycle-integrated pyridine scaffolds. [30][31][32][33][34][35][36] In this work, we focus on discussion of the various reported procedures for the synthesis of fused and binary steroidal pyridines and their structural importance, in addition to highlighting their biological significance.…”

Recent progress in the chemistry of β-aminoketones

“…This study is in continuation of our preceding plans and reports on emphasizing the chemistry of heterocycles with active moieties in the synthesis of heterocyclic compounds with varying biological activities and their impact in the elds of pharmaceutical and medicinal chemistry. [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] The literature survey deals with the scope of synthetic approaches applied for the synthesis of b-aminoketones and ascertaining their reactivity against reactions with diverse reagents.…”

Insights into the medicinal chemistry of heterocycles integrated with a pyrazolo[1,5-a]pyrimidine scaffold

“…48 On the other hand, the chemistry of bicyclic systems and their use in pharmaceutical and medicinal fields attracted researchers' interest in recent years. [49][50][51][52][53][54][55][56][57][58] A comprehensive study of the synthetic routes adopted to prepare pyrazoloij1,5a]pyrimidines has recently been published including all the synthetic courses from aminopyrazoles with different reagents or acyclic reactants under basic or acidic or mild conditions. 59 Also, other reviews discussed the protocols concerned for the synthesis of pyrazoloij1,5-a]pyrimidines with a non-comprehensive study.…”