Synthesis of Alkynyl Ketones by Sonogashira Cross-Coupling of Acyl Chlorides with Terminal Alkynes Mediated by Palladium Catalysts Deposited over Donor-Functionalized Silica Gel

Palladium catalysts deposited over silica gel bearing simple amine (≡Si(CH2)3NH2) and composite functional amide pendants equipped with various donor groups in the terminal position (≡Si(CH2)3NHC(O)CH2Y, Y = SMe, NMe2 and PPh2) were prepared and evaluated in Sonogashira-type cross-coupling of acyl chlorides with terminal alkynes to give 1,3-disubstituted prop-2-yn-1-ones. Generally, the catalysts showed good catalytic activity in the reactions of aroyl chlorides with aryl alkynes under relatively mild reaction conditions even without adding a copper co-catalyst. However, their repeated use was compromised by a significant loss of activity after the first catalytic run.

Highly stereoselective heterogeneous palladium-catalyzed transfer semihydrogenation of internal alkynes to access cis-alkenes

A highly efficient heterogeneous palladium-catalyzed transfer semihydrogenation of internal alkynes was achieved in dimethylformamide at 145 ºC by using an MCM-41-immobilized bidentate nitrogen palladium(II) complex [MCM-41-2N-Pd(OAc)2] as catalyst and dimethylformamide/KOH as hydrogen source, yielding a variety of cis-alkenes in good to high yields with excellent stereoselectivity. This supported palladium catalyst can be easily recovered by filtration of the reaction solution and recycled up to seven times with almost consistent activity.

One-pot regioselective synthesis of substituted pyrazoles and isoxazoles in PEG-400/water medium by Cu-free nano-Pd catalyzed sequential acyl Sonogashira coupling–intramolecular cyclization

Catalyst efficacy of in situ generated Pd-nanoparticles in the regioselective one-pot synthesis of substituted pyrazoles and isoxazoles via sequential coupling-cyclization methodology in environmentally benign medium is described.

A phosphine-free, heterogeneous palladium-catalyzed atom-efficient carbonylative cross-coupling of triorganoindiums with aryl halides leading to unsymmetrical ketones

A phosphine-free heterogeneous palladium-catalyzed carbonylative cross-coupling of triorganoindiums with aryl halides for the synthesis of unsymmetrical ketones has been described.

Copper-catalyzed three-component reactions of phenols, acyl chlorides and Wittig reagents for the synthesis of β-aryloxyl acrylates

A new protocol towards the diversity-oriented synthesis of β-aryloxyl acrylates has been developed using simple reactants and catalyst.

A new class of pyrenyl solid-state emitters: 1-pyrenyl ynones. Synthesis via the Friedel–Crafts route, molecular and electronic structure and photophysical properties

Friedel-Crafts acylation of pyrene with alkynoic acids in the presence of trifluoroacetic anhydride and triflic acid constitutes a direct and efficient route to 1-pyrenyl ynones fluorescent in solution and in the solid state.