A pyridine-catalyzed ylide cyclization affording dihydrofurans and dihydropyrroles has been developed. In the presence of a catalytic amount of pyridine and Fe(Tcpp)Cl, α-ylidene-β-diketones and α,β-unsaturated imines react with diazoacetates providing dihydrofurans and dihydropyrroles respectively, in up to 96% yield with high diastereoselectivities.

Both alkylarylalkynes and diarylalkynes 1 are converted into the α-diketones 2 in good yield by the use of mercuric salts, e.g., mercuric nitrate hydrate or mercuric triflate, in the presence of water. Other mercuric salts, e.g., sulfate, chloride, acetate, or trifluoroacetate, do not provide the diketone product. A possible mechanism is proposed.

Gold-catalyzed O-vinylation of cyclic 1,3-diketones has been achieved for the first time, which provides direct access to various vinyl ethers. A catalytic amount of copper triflate was identified as the significant additive in promoting this transformation. Both aromatic and aliphatic alkynes are suitable substrates with good to excellent yields.

The organocatalytic Michael addition of malonates to symmetric unsaturated 1,4-diketones catalyzed by thiourea and squaramide derivatives with Cinchona alkaloids afforded the formation of a new C-C bond in high yields (up to 98%) and enantiomeric purities (up to 93%). The absolute configuration of the product was suggested from comparison of the experimental and calculated VCD spectra of the re...

A series of novel 1,4diazepines have been synthesized from β-diketones / β-ketoesters of 4acetylaminobenzene sulphonyl chloride. Desired compounds were prepared by the reaction of novel βdiketone / β-ketoester derivatives of [N4-(4acetylamino) benzene sulphonyl piperazinylN1-1bromopropane] with ethylenediamine to get 1, 4dizapines. All the newly synthesized compounds were characterized with IR ...

Different synthetic routes leading to terpyridines functionalised with furan heterocycles are reviewed. The methodologies used to prepare such compounds include the ring closure of 1,5-diketones and cross-coupling reactions. These versatile terpyridines and their derived metal complexes find applications in various fields including coordination chemistry, medicinal chemistry and material sciences.

The photodynamics in symmetric and unsymmetric β-diketones are studied with transient absorption in the deep-UV. Excitation leads to ultrafast ESIPT while further relaxation and isomerization processes depend on the molecular symmetry and solvent environment. OCIS codes: (320.7150) Ultrafast spectroscopy; (300.6540) Spectroscopy, ultraviolet; (190.7110) Ultrafast nonlinear optics

Ambiphilic allenes are generated by an organocatalyzed domino reaction of alkyl propiolates and aromatic 1,2-diketones; in the absence of any external chemical agent, these allenes perform a thermally-driven dimerization reaction to generate the corresponding fully-substituted cyclobutanes in a regio- and highly stereoselective manner.

An intriguing new Wacker-type oxidation of alkynes catalyzed by PdBr(2) and CuBr(2) is described, which opens an efficient access to 1,2-diketones using molecular oxygen. Under the optimized conditions, a variety of alkynes, including diarylalkynes, arylalkylalkynes, and dialkylalkynes, were compatible substrates in this transformation. The mechanism of this reaction was preliminarily investiga...

Difluoromethyl ketones are an under-studied class of ketones which have great potential as useful building blocks for materials and drug design. Here we report a simple and convenient synthesis of this class of compounds via a one-pot difluorination/fragmentation of 1-trifluoromethyl-1,3-diketones which should now allow the chemistry of difluoromethyl ketones to be fully developed.