Lewis Acid-Promoted Ring-Contraction of 2,4,6,8-Tetrasubstituted 1,5-Diazacyclooctatetraenes to 2,4,6-Trisubstituted Pyridines

Ring-contraction of 2,4,6,8-tetrasubstituted 1,5-diazacyclooctatetraenes was highly efficiently promoted by Lewis acid such as TiCl₄, affording 2,4,6-trisubstituted pyridines in excellent yields, along with release of a nitrile. A reaction mechanism involving a 6π electrocyclic ring-closing followed by a retro [2 + 2] cyclization of an 1-azetine moiety was supported by both experimental observations and density functional theory calculation.

Photoinduced fragmentation-rearrangement sequence of cycloketoxime esters

A novel rearrangement of cycloketoxime esters to cyano-containing benzoates beyond the traditional Beckmann and Neber rearrangement process has been established in the presence of photocatalysis catalysis.

Modular 2,3-diaryl-2H-azirine synthesis from ketoxime acetates via Cs2CO3-mediated cyclization

A practical and effective Cs₂CO₃-mediated cyclization of ketoxime acetates for the synthesis of 2H-azirines has been developed.

Elemental tellurium mediated synthesis of 2-(trifluoromethyl)oxazoles using trifluoroacetic anhydride as reagent

An elemental tellurium mediated synthesis of 2-(trifluoromethyl)oxazoles from the reaction of acetophenone oxime acetates with trifluoroacetic anhydride is described.

Copper-catalyzed coupling of oxime acetates and aryldiazonium salts: an azide-free strategy toward N-2-aryl-1,2,3-triazoles

An azide-free strategy for the synthesis of N-2-aryl-1,2,3-triazoles via copper-catalyzed coupling of oxime acetates and aryldiazonium tetrafluoroborates.

Synthesis of polysubstituted pyridines from oxime acetates using NH4I as a dual-function promoter

An NH₄I dual-function promoter enables pyridine synthesis through oxime N–O bond reduction and subsequent condensation reactions.

Cu-Catalyzed switchable synthesis of functionalized pyridines and pyrroles

A switchable synthesis of functionalized pyridines and pyrroles via Cu-catalyzed cascade reactions with N-sulfonyl azadienes and alkynes.

I2-Triggered N–O cleavage of ketoxime acetates for the synthesis of 3-(4-pyridyl)indoles

An I₂-triggered condensation annulation of aryl ketoxime acetates and 3-formylindoles to produce diverse 3-(4-pyridyl)indoles via generating iminyl radicals.