Novel fluoro-substituted benzo- and benzothieno fused pyrano[2,3-c]pyrazol-4(1H)-ones

Diastereoselective Synthesis of 2‐(1,3‐Dioxolanes‐4‐yl)‐4H‐pyran‐4‐ones from 2‐Diazo‐3,5‐dioxo‐6‐ynoates (sulfones) and Aldehydes Based on Tandem Cyclization‐Cycloaddition Strategy

“…1,3‐Dioxolanes also possess biological activity, and has been employed as inhibitors (Figure ) . Numerous methods for the construction of γ‐pyranone and 1,3‐dioxolane skeleton have been developed . For example, oxidation‐cyclization (Scheme a) and tandem cyclization strategies (Scheme b) for the construction of γ‐pyranone core have been disclosed in literatures.…”

Copper-Catalyzed Tandem O-Arylation–Oxidative Cross Coupling: Synthesis of Chromone Fused Pyrazoles

“…Continuing our interest in the development of tandem reactions triggered by copper catalysis, we envisaged to develop a tandem O-arylation–oxidative coupling process. To test this hypothesis, we have selected 2,4-dihydro-3 H -pyrazol-3-ones 1 and 2-haloaryl aldehydes 2 as coupling partners that would eventually lead to the synthesis of chromone fused pyrazoles, chromeno­[2,3- c ]­pyrazol-4­(1 H )-ones 3 (Figure , iii). , Indeed, this kind of chromone fused pyrazole has shown important biological activities such as selective (A 2A or A 1 ) adenosine receptor antagonist . It should be mentioned that the chromone fused pyrazoles have been prepared using a multistep synthesis associated with harsh reaction conditions, use of excess amounts of reagents/oxidants, prolonged reaction times, and with the outcome of low overall yields ,,, (for example, see Figure , iv).…”

Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

“…In continuation of our program regarding the synthesis of fluoro- and trifluoromethyl-substituted pyrazoles and annulated pyrazoles [8–9] we here present the synthesis of trifluoromethyl-substituted pyrazolo[4,3- c ]pyridines. The latter heterocyclic system represents the core of several biologically active compounds, acting, for instance, as SSAO inhibitors [10], or inhibitors of different kinases (LRRK2 [11–12], TYK2 [13], JAK [14–15]).…”