Copper-Catalyzed Ring-Opening Defluorinative Alkylation of Siloxydifluorocyclopropanes: Synthesis of γ-Fluoro-δ-Ketoesters and γ,δ-Diketonitriles

Metal-Free Decarboxylative Cyanomethylation of β-Aryl/Heteroaryl Substituted α,β-Unsaturated Carboxylic Acids to γ-Ketonitriles

A decarboxylative cyanomethylation of β-aryl/heteroaryl substituted α,β-unsaturated carboxylic acids has been accomplished via C(sp3)-H activation of alkyl nitriles to afford diverse γ-ketonitriles by making use of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and tert-butyl hydroperoxide (TBHP). The present report offers a metal-free approach and is featured with a broad substitution pattern and functional group compatibility.

Bicyclization of 4-Cyano-1,2-diketones with Amidines: Synthesis of Tetrahydroimidazo[4,5-b]-5-pyridinones

A new bicyclization of 4-cyano-1,2-diketones with amidines is reported for the construction of tetrahydro-5H-imidazo[4,5-b]pyridin-5-ones. The tandem reaction is proposed to involve the double condensation-cyclization of diketone with amidine, an α-ketol like rearrangement, the hydrolysis of nitrile followed by intramolecular nucleophilic addition, and the elimination of water. Features of the bicyclization method include high yields, good functional group tolerance, and mild reaction conditions.

(2-Fluoroallyl)pyridinium tetrafluoroborates: novel fluorinated electrophiles for Pd-catalyzed allylic substitution

An efficient two-step approach to 2-fluoroallyl amines was developed that involves the synthesis of (2-fluoroallyl)pyridinium tetrafluoroborates from readily available gem-bromofluorocyclopropanes and the application of the former as novel and stable 2-fluoroallyl electrophiles for Pd-catalyzed allylic substitution.