Giansalvo Pinna

Synthesis of Tricyclic Condensed Rings Incorporating the Pyrazole or Isoxazole Moieties Bonded to a 4-Piperidinyl Substituent

In this paper we report the synthesis of new compounds based on the pyrazole and isoxazole framework fused to a cycloalkene unit, and bearing as a substituent the 1-piperidinyl group as new examples of potential antipsychotic molecules. The general synthesis involves the acylation of a chloro-substituted cyclic ketone with a 1-substituted piperidine-4-carboxylate derivative, followed by heterocyclization of the formed 1,3-dioxo compound with a hydrazine or hydroxylamine.

Novel pyrrolocycloalkylpyrazole analogues as CB1 ligands

Novel 1,4‐dihydropyrazolo[3,4‐a]pyrrolizine‐, 4,5‐dihydro‐1H‐pyrazolo[4,3‐g]indolizine‐ and 1,4,5,6‐tetrahydropyrazolo[3,4‐c]pyrrolo[1,2‐a]azepine‐3‐carboxamide‐based compounds were designed and synthesized for cannabinoid CB1 and CB2 receptor interactions. Any of the new synthesized compounds showed high affinity for CB2 receptor with Ki values superior to 314 nm, whereas some of them showed moderate affinity for CB1 receptor with Ki values inferior to 400 nm. 7‐Chloro‐1‐(2,4‐dichlorophenyl)‐N‐(homopiperidin‐1‐yl)‐4,5‐dihydro‐1H‐pyrazolo[4,3‐g]indolizine‐3‐carboxamide (2j) exhibited good affinity for CB1 receptor (KiCB1 = 81 nm) and the highest CB2/CB1 selectively ratio (>12). Docking studies carried out on such compounds were performed using the hCB1 X‐ray in complex with the close pyrazole analogue AM6538 and disclosed specific pattern of interactions related to the tricyclic pyrrolopyrazole scaffolds as CB1 ligands.

Osmium complexes in catalysis of olefin hydrogenation and isomerization

This review focuses on the evolution of the use of osmium complexes as catalysts in the hydrogenation and isomerization of olefins. Osmium systems show good catalytic activities and selectivities in the hydrogenation of olefins via both dihydrogen and transfer hydrogenation. Such systems therefore have significant potential to become a powerful tool in organic synthesis.