Synthesis of Non‐Terminal Alkenyl Ethers, Alkenyl Sulfides, and N‐Vinylazoles from Arylaldehydes or Diarylketones, DMSO and O, S, N‐Nucleophiles

Abstract

A transition‐metal‐free protocol for the synthesis of non‐terminal alkenyl ethers, alkenyl sulfides, and N‐vinylazoles from arylaldehydes or diarylketones, DMSO and O, S, N‐nucleophiles has been reported. In this protocol, 24 examples of non‐terminal alkenyl ethers and 28 examples of non‐terminal alkenyl sulfides in 72–95% yields have been synthesized within 5 min. Moreover, 27 examples of non‐terminal N‐vinylazoles with 57–88% yields have also been synthesized within 2 hours. The preliminary mechanism investigations revealed that arylaldehydes or diarylketones offered a carbon atom, DMSO provided a methine and O, S, N‐nucleophiles contributed one X atom for constructing C=C−X structure.

Photochemical halogen-bonding assisted generation of vinyl and sulfur-centered radicals: stereoselective catalyst-free C(sp2)–S bond forming reactions

“…1 In particular, the synthesis of vinyl sulfides is particularly appealing due to their presence in biologically active molecules 2 and building blocks in organic synthesis. 3 Classical thermal approaches for the preparation of these compounds typically implicate the use of either an alkenyl halide or an alkyne and a sulfur precursor (commonly, a thiol or a disulfide species) as the partner reagents for the synthesis of the desired cross-coupling products (Scheme 1a). 4 However, the unavoidable, mandatory employment of metal catalysts, strong oxidants, harsh conditions or starting materials that are difficult to synthesize hampers the sustainability and simplicity of these methodologies.…”

One‐Step Synthesis of Arylacetaldehydes from Aryl Aldehydes or Diaryl Ketones via One‐Carbon Extension by Using the System of DMSO/KOH/Zinc

“…Recently, we have reported a method for the synthesis of alkenyl ethers via the three‐component reaction of aryl aldehydes or diaryl ketones, O‐nucleophiles, and DMSO in the KOH/DMSO system [15] . Encouraged by this result and considering the role of zinc in the preparation of arylacetaldehydes is to provide a stable environment for arylacetaldehydes, we surmised that the addition of glycols to this reaction system can achieve the synthesis of arylacetaldehyde acetals from aryl aldehydes or diaryl ketones in the absence of zinc.…”

“…The reaction was sensitive to temperature, both elevating and decreasing the reaction temperature led to dramatically decreased yield (Table 1, entries 11, 12). It was worth noting that the yield of the product was decreased when changing the amount of KOH and Zn (entries [13][14][15][16]. When the reaction was performed under O 2 atmosphere, the 3 a could not be obtained (Table 1, entry 17).…”

Highly Regioselective Dichalcogenation of Alkenyl Sulfonium Salts to Access 1,1-Dichalcogenalkenes

“…1 The synthesis of thioalkenes is particularly appealing because of their unique properties and applications in organic chemistry, materials, and life science. 1,2 The traditional thiolation of alkenyl halides via C(alkenyl)−S cross-coupling usually provides monothioalkenes enabled by transition metal catalysis or photocatalysis, 3 and dithiolation of the corresponding alkenyl dihalides affords dithioalkenes accordingly (Scheme 1A). 4 Comparatively, dithioalkenes, especially 1,1-dithioalkenes, have been less investigated.…”