This study describes the development of Rh-catalyzed [2,3]-sigmatropic rearrangement of alkynyl carbenes with allyl sulfides. The protocol exhibits equitable functional group tolerance and allows the formation of a variety of synthetically valuable sulfide-substituted 1,5-enyne products. To the best of our knowledge, this is the first example of [2,3]-sigmatropic rearrangement of alkynyl carbenes. DFT analysis supports the involvement of rhodium carbene generation, sulfonium ylides formation, and [2,3]-sigmatropic rearrangement pathway.

A cobalt-catalyzed decarboxylative oxyalkylation of styrenes with α-cyanoacid has been established, leading to a variety of γ‑ketonitriles in moderate yields. α-Cyanoacid was applied as the nitrile sources. This methodology was distinguished by operational simplicity, easily available starting materials and good functionality tolerance.

The [4+1] cyclization reaction of 2-hydroxylimides and trimethylsulfoxonium iodide was investigated.

NiMn layered double hydroxide (Ni3Mn-LDH) has been found to be an efficient catalyst for the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) using molecular oxygen as the sole oxidant. Various reaction conditions on the oxidation have been investigated, and impressive catalytic performance, good stability and recyclability have been observed for Ni3Mn-LDH. Both of Ni2+ and Mn3+ species in the structure were proposed to be the catalytically active site for the aerobic oxidation of HMF, and the two species in the transformation exhibited synergistic effect.

An iron-catalysed aerobic oxidative C–C bond cleavage of ketones for the synthesis of primary amides has been developed using TEMPO and oxygen as an oxidant. This reaction tolerates a wide range of substrates, and primary amides are obtained in good to excellent yields. Substrates with long-chain alkyl substituents could also be selectively cleaved and converted into the corresponding amides.

Abstract An efficient approach for the amination of vinyl azides with N,N-dialkylacylamides has been developed. By using this protocol, structurally important α-ketoamides can be easily synthesized. The key to success is not only the introduction of a Cu(I)/oxygen catalytic system but also the utilization of t-BuOCl and benzoic acid as additives. The reaction is operationally simple, scalable, and displays broad scope and functional group tolerance. A possible mechanism involving copper-catalyzed oxidative generation of peroxide radicals is proposed.

Cyclic ketones tethered with a vinyl azide group undergo a Schmidt-hydrolysis sequence to give secondary lactams bearing a ketone side chain. Secondary lactams are obtained in a regioselective manner that is not possible in a conventional Schimdt reaction. In addition to the well-documented C-2 nucleophilicity, the N nucleophilicity of vinyl azide disclosed in this work opens a new direction for reaction invention involving vinyl azides.

A Fe-catalyzed highly regioselective α,β-difunctionalization of vinylarenes with diphenylphosphine oxides and anilines is disclosed, in which α,β-aminophosphinoylation is efficiently and conveniently constructed under mild conditions with good functional compatibility and a broad substrate scope. The control experiments have revealed a radical reaction pathway.

A novel highly selective Ag-catalyzed intermolecular amination of fluoroarenes has been developed. This transformation starts from readily available 4-carbonyl fluorobenzene and NaN3 or other nitrogen-source, via amination followed by C-F bond cleavage, thus affording the desired 4-carbonyl arylamine products under mild conditions. The reaction is accelerated using a small amount of water. This pathway is distinct from a previously reported radical amination reaction.

A silver catalyzed decarboxylative C(sp2)-C(sp3) coupling of vinylic carboxylic acids with alcohols, alkylbenzenes, cycloalkanes and cyclic ethers was developed by using DTBP as an oxidant. This reaction tolerates a wide range of substrates, and products are obtained in good to excellent yields. The reaction also shows good stereoselectivity, and only trans-isomers are obtained. In addition, a radical pathway would be involved to facilitate this decarboxylative C(sp2)-C(sp3) coupling reaction.