Copper-Catalyzed Three-Component Redox-Neutral Ring Opening of Benzothiazoles to 1-Amino-N-(2-(phenylthio)phenyl)methanimine

Dearomative Ring-Opening of N-Fused Heteroarenes: Access to Tetrasubstituted Alkenes and Ketimines

We report a novel and efficient strategy for constructing tetrasubstituted alkenes and α-iminonitriles from 3-aminoindolizines and 3-aminoimidazo[1,2-a]pyridines. This approach involves a dearomative ring-opening of N-fused heteroaromatic amines coupled to a DDQ-mediated oxidative process under mild, metal-free conditions. The methodology demonstrates broad substrate scope, excellent functional group tolerance, and scalability, offering a versatile platform for synthesizing complex alkenes and nitrile-containing frameworks.

Novel multitarget directed ligands inspired by riluzole: A serendipitous synthesis of substituted benzo[b][1,4]thiazepines potentially useful as neuroprotective agents

Riluzole, the first clinically approved treatment for amyotrophic lateral sclerosis (ALS), represents a successful example of a drug endowed with a multimodal mechanism of action. In recent years, different series of riluzole-based compounds have been reported, including several agents acting as Multi-Target-Directed Ligands (MTLDs) endowed with neuroprotective effects. Aiming at identical twin structures inspired by riluzole (2a-c), a synthetic procedure was planned, but the reactivity of the system took a different path, leading to the serendipitous isolation of benzo[b][1,4]thiazepines 3a-c and expanded intermediates N-cyano-benzo[b][1,4]thiazepines 4a-c, which were fully characterized. The newly obtained structures 3a-c, bearing riluzole key elements, were initially tested in an in vitro ischemia/reperfusion injury protocol, simulating the cerebral stroke. Results identified compound 3b as the most effective in reverting the injury caused by an ischemia-like condition, and its activity was comparable, or even higher than that of riluzole, exhibiting a concentration-dependent neuroprotective effect. Moreover, derivative 3b completely reverted the release of Lactate Dehydrogenase (LDH), lowering the values to those of the control slices. Based on its very promising pharmacological properties, compound 3b was then selected to assess its effects on voltage-dependent Na+ and K+ currents. The results indicated that derivative 3b induced a multifaceted inhibitory effect on voltage-gated currents in SH-SY5Y differentiated neurons, suggesting its possible applications in epilepsy and stroke management, other than ALS. Accordingly, brain penetration was also measured for 3b, as it represents an elegant example of a MTDL and opens the way to further ex-vivo and/or in-vivo characterization.

Bifunctionalization of styrene through ring-opening-recombination strategy of phenylpropathiazole salt

By opening the ring of a benzothiazole salt, we provide a sulfur source for the bifunctional reaction of styrene. The ring-opening-recombination reaction of the benzothiazole salt simultaneously constructs new C-S, C-O, and CO bonds after C-S bond breaking. The reaction proceeds in green solvents, requires no transition metal catalyst, and is compatible with many functional groups.

Cu(II)-Catalyzed C-N, C-O, C-Cl, C-S, and C-Se Bond Formation via C(sp2)-H Activation Using 7-Azaindole as an Intrinsic Directing Group

A general protocol has been developed for the construction of carbon-heteroatom (C-N, C-Cl, C-O, C-S, and C-Se) bonds using the bench stable, earth-abundant, and environmentally benign copper catalyst. Only oxygen is sufficient to regenerate the copper catalyst. Control experiments suggested that the proto-demetalation step is reversible. Depending on the coupling partner, the reaction follows either disproportionation or radical pathways to complete the catalytic cycle. The synthetic utility of the developed protocol has been demonstrated via various functional group transformations.

Pd/NBE-catalyzed sequential carbamoylation/olefination of aryl iodides

We present a Pd/NBE-catalyzed sequential carbamoylation/olefination of aryl iodides under mild reaction conditions, which provide diverse 4-methylene-3,4-dihydro-1(2H)-isoquinolin-1-one analogues.