I₂/DMSO-Promoted Synthesis of Diaryl Sulfide- and Selenide-Embedded Arylhydrazones

Abstract

Functionalization and derivatization of arylhydrazones are important in pharmaceutical, medicinal, material, and coordination chemistry. In this regard, a facile I2/DMSO-promoted cross-dehydrogenative coupling (CDC) for direct sulfenylation and selenylation of arylhydrazones has been accomplished utilizing arylthiols/arylselenols at 80 °C. This method provides a metal-free benign route for the synthesis of a variety of arylhydrazones embedded with diverse diaryl sulfide and selenide moieties in good to excellent yield. In this reaction, molecular I2 acts as a catalyst, and DMSO is utilized as a mild oxidant as well as solvent to produce several sulfenyl and selenyl arylhydrazones through a CDC-mediated catalytic cycle.

Efficient Synthesis of Fully Substituted and Diversely Functionalized Pyrazoles through p‐TSA Catalyzed One‐Pot Condensation of Cyclic β‐Diketones, Arylglyoxals and Arylhydrazones

“…Notably, the reaction efficiently introduced chloro-pyridylhydrazone 3 to access the desired product 4 aa in 83 % yield. With such satisfactory results, the utility and robustness of the present condensation reaction was further verified by employing diaryl sulfide-and selenide-embedded arylhydrazones [31] which delivered a novel class of fully substituted N-functionalized 3hydroxy-2-pyrazolyldimidones (4 ab & 4 ac) containing biologically active diarylsulfide/selenide moieties in high yield (79- temp.…”

“…The mixture was stirred further at 70 °C for 2 h. [b] Isolated yield (%). General experimental procedure for synthesis of starting materials aryl glyoxals (2) and arylhydrazones (3): The starting material aryl glyoxals (2 a-h) [30,[34][35][36][37][38][39][40] and arylhydrazones (3 a-z and 3 aaac) [30,31,[41][42][43][44][45][46][47][48][49][50][51][52] were synthesized according to the reported procedure (see Supporting Information).…”

Elemental Sulfur Promoted Cyclization of Aryl Hydrazones and Aryl Isothiocyanates Yielding 2-Imino-1,3,4-thiadiazoles

“…All reagents and starting materials were commercially obtained and were used without further purification unless otherwise noted. The hydrazone substrates were prepared according to the literature . Gas chromatography (GC) analyses were performed using Shimadzu Nexis GC-2030 equipped with a flame ionization detector (FID) and an SPB-5 column (length = 30 m, inner diameter = 0.25 mm, and film thickness = 0.25 μm).…”

Review of application of the I2 and dimethyl sulfoxide combined reagent system to aryl methyl ketones for diverse transformations

“…4 The combination reagent of I 2 and DMSO has shown unique and attractive reactivity in organic synthesis, and it has been successfully applied to oxidation, oxidative cross-coupling, functionalization, and the construction of heterocyclic rings through cascade cyclization because of its green, high efficiency, and mild reaction conditions. 5–8…”