Synthesis of N-Acyl-5-aminopenta-2,4-dienals via Base-Induced Ring-Opening of N-Acylated Furfurylamines: Scope and Limitations

Facile synthesis of N-(α-furanyl) alkyl sulfoximines via gold catalyzed Michael addition/cyclization of enynones and sulfoximines

Herein, we prepare a new array of N-(α-furanyl) alkyl sulfoximines via a gold catalyzed reaction of enynone with sulfoximine in moderate to very good yields. The reaction involves Michael addition of sulfoximine to enynone, followed by intramolecular cyclization. The presence of two chiral centres led to the formation of a mixture of diastereomers approximately in a 1 : 1 ratio. The salient features of the protocol include broad substrate scope, high efficiency and high yields. The synthetic utility of the protocol is explored using Suzuki-Miyaura cross-coupling and mild, metal-free opening of the furan ring.

New aryl and acylsulfonamides as state-dependent inhibitors of Nav1.3 voltage-gated sodium channel

Voltage-gated sodium channels (Na_vs) play an essential role in neurotransmission, and their dysfunction is often a cause of various neurological disorders. The Na_v1.3 isoform is found in the CNS and upregulated after injury in the periphery, but its role in human physiology has not yet been fully elucidated. Reports suggest that selective Na_v1.3 inhibitors could be used as novel therapeutics to treat pain or neurodevelopmental disorders. Few selective inhibitors of this channel are known in the literature. In this work, we report the discovery of a new series of aryl and acylsulfonamides as state-dependent inhibitors of Na_v1.3 channels. Using a ligand-based 3D similarity search and subsequent hit optimization, we identified and prepared a series of 47 novel compounds and tested them on Na_v1.3, Na_v1.5, and a selected subset also on Na_v1.7 channels in a QPatch patch-clamp electrophysiology assay. Eight compounds had an IC₅₀ value of less than 1 μM against the Na_v1.3 channel inactivated state, with one compound displaying an IC₅₀ value of 20 nM, whereas activity against the inactivated state of the Na_v1.5 channel and Na_v1.7 channel was approximately 20-fold weaker. None of the compounds showed use-dependent inhibition of the cardiac isoform Na_v1.5 at a concentration of 30 μM. Further selectivity testing of the most promising hits was measured using the two-electrode voltage-clamp method against the closed state of the Na_v1.1-Na_v1.8 channels, and compound 15b displayed small, yet selective, effects against the Na_v1.3 channel, with no activity against the other isoforms. Additional selectivity testing of promising hits against the inactivated state of the Na_v1.3, Na_v1.7, and Na_v1.8 channels revealed several compounds with robust and selective activity against the inactivated state of the Na_v1.3 channel among the three isoforms tested. Moreover, the compounds were not cytotoxic at a concentration of 50 μM, as demonstrated by the assay in human HepG2 cells (hepatocellular carcinoma cells). The novel state-dependent inhibitors of Na_v1.3 discovered in this work provide a valuable tool to better evaluate this channel as a potential drug target.

Recent developments in the synthesis and applications of furopyrazoles

This review aims to describe the different strategies developed so far for the synthesis of furopyrazoles and their biological and pharmacological properties.

Cascade process for direct synthesis of indeno[1,2-b]furans and indeno[1,2-b]pyrroles from diketene and ninhydrin

Novel and efficient multicomponent reactions (MCRs) involving diketene, ninhydrin (indane-1,2,3-trione) and one primary amine (3CR) or two different primary amines (4CR) were achieved for the successful synthesis of dihydro-4H-indeno[1,2-b]furan-3-carboxamides or tetrahydroindeno[1,2-b]pyrrole-3-carboxamides, respectively. The merits of this method are highlighted by using either commercially available or easily accessible starting materials, operational simplicity, facile workup procedure, efficient usage of all the reactants, tolerance of a variety of functional groups and ability to conduct under un-catalyzed reaction condition. The products were also isolated by just decantation of the solvent, and for the purification column chromatography was non-required.

A General Synthetic Route to Isomeric Pyrrolo[1,2- x][1,4]diazepinones

A simple one-pot method for the synthesis of isomeric pyrrolo[1,2- x][1,4]diazepinones in reasonable yields was developed. The method is based on the condensation of readily available N-Boc amino acids with biomass-derived furans containing aminoalkyl groups followed by deprotection, furan ring opening, and Paal-Knorr cyclization. Using this approach, we synthesized pyrrolo[1,2- a][1,4]diazepin-3(2 H)-ones from furfurylamines and β-amino acids and pyrrolo[1,2- d][1,4]diazepin-4(5 H)-ones from 2-(2-furyl)ethylamines and α-amino acids. The cytotoxicity of the synthesized pyrrolodiazepinones was studied.