A General Cyclocarbonylation of Aryl Bromides and Triflates with Acetylenes: Palladium-Catalyzed Synthesis of 3-Alkylidenefuran-2-ones

Electrosynthesis of dimeric butenolides by C-C-homocoupling in the oxidation of 2,4-diarylfurans under aqueous conditions

Fast and efficient galvanostatic conversion of 2,4-diarylfurans into dimeric furan-2(5H)-ones is now possible in one pot and good yields at room temperature in sustainable aqueous organic solvent. Recent applications of these highly desired structures demand our attention since they are a versatile alternative to acrylates in polymerization to achieve green materials. The reaction mechanism proposal, supported by density functional theory (DFT) theoretical calculations, involves furanoxy radicals, detected by electron paramagnetic resonance (EPR), as the last intermediate before a homocoupling step that affords butenolides. The process can be successfully extended to an array of electron-donating and electron-withdrawing substituents on the aromatic ring. The proposed pathways to explain the formation of the products are rationalized and discussed. A concomitant oxidation of water to hydroxyl radicals is not discarded, particularly with electron-withdrawing substituents at the aromatic ring. In addition, the biological activity as biocides of the obtained compounds was tested, and they showed promising activity against Staphylococcus aureus.

Recyclable Copper(I)-Catalyzed Cross-Coupling of Trialkylsilylethynes and N-Tosylhydrazones Leading to the Formation of C(sp)-C(sp3) Bonds

A highly efficient heterogeneous copper(I)-catalyzed cross-coupling of trialkylsilylethynes with N-tosylhydrazones has been achieved in dioxane at 90-110 °C via the Cu carbene migratory insertion with an SBA-15-immobilized l-proline-Cu(I) complex [SBA-15-l-Proline-CuI] as the catalyst and LiO^tBu as the base, leading to the formation of C(sp)-C(sp³) bonds. The reaction generates a wide variety of alkyltrialkylsilylalkynes in moderate to high yields. This new heterogenized copper(I) complex exhibits a comparable catalytic efficiency to homogeneous CuI and can be easily recovered through a simple centrifugation process and is recyclable up to 12 times without a remarkable loss of activity.

Featuring Xantphos

This review highlights the use of the bisphosphine ligand group in homogeneous catalysis.

Stereoselective synthesis of E-3-(arylmethylidene)-5-(alkyl/aryl)-2(3H)-furanones by sequential hydroacyloxylation-Mizoroki–Heck reactions of iodoalkynes

Stereoselective hydroacyloxylation of iodoalkynes with β-aryl cinnamic acids and subsequent Mizoroki–Heck reaction provides an efficient route to substituted 2(3H)-furanones.

Pd-catalysed carbonylative annulation of salicylaldehydes with benzyl chlorides using N-formylsaccharin as a CO surrogate

A highly efficient synthesis of 3-arylcoumarins by Pd-catalysed carbonylative cyclisation of salicylaldehydes with benzyl chlorides using N-formylsaccharin as a CO source is developed.

Palladium-Catalyzed One-Pot Carbonylative Sonogashira Reaction Employing Formic acid as the CO Source

A convenient palladium-catalyzed carbonylative coupling of aryl iodides and terminal alkynes with formic acid as the CO precursor has been developed. A variety of alkynones were obtained in good yields in a one-pot manner for the first time.

Palladium-catalyzed oxidative carbonylative coupling of arylboronic acids with terminal alkynes to alkynones

The first example of palladium-catalyzed oxidative carbonylation of arylboronic acids with terminal alkynes has been developed. By an appropriate combination of a palladium salt, a ligand, and an oxidant, the desired alkynones were isolated in moderate to good yields.