Rh2(OAc)4-catalyzed reactions of alpha-diazoimides: a simple and novel synthesis of mono- and bis(2,3-fused perhydrooxazol-4-one) systems.

Simply, trapping the intermediate isomünchnone 1,3-dipoles by the external oxygen nucleophiles resulted in new heterocyclic systems and the use of diols led to the formation of four carbon-oxygen bonds in a single operation which eventually delivered bis(2,3-fused perhydrooxazol-4-one) systems.

Tandem cyclization-cycloaddition behavior of rhodium carbenoids with carbonyl compounds: stereoselective studies on the construction of novel epoxy-bridged tetrahydropyranone frameworks.

Investigations and stereoselective studies on the tandem reactions of carbonyl ylides generated from alpha-diazo ketones in the presence of carbonyl compounds are presented in this paper. Intramolecular cyclization of rhodium carbenoids generated the transient five- or six-membered-ring carbonyl ylide dipoles, which efficiently underwent 1,3-dipolar cycloaddition reactions with various dipolarophiles such as aromatic aldehydes 15, alpha,beta-unsaturated aldehydes 18/24, alpha,beta-unsaturated ketones 27/28/31, and dienone 34. The transient carbonyl ylides underwent cycloadditions with various aromatic aldehydes to furnish diverse epoxy-bridged tetrahydropyranone ring systems in a diastereoselective manner.

First example of regiospecific intermolecular C-H insertion reactions of cyclic rhodium carbenoids: novel synthesis of 3-indol-3'-yloxindoles.

Facile regiospecific intermolecular C-H insertion reactions of cyclic rhodium carbenoids have been achieved using diazo carbonyl compounds 1 and indole or N-substituted indoles to afford 1,3-dihydro-1'H-[3,3']biindolyl-2-ones, 3a-o in an excellent yield.

Dimesitylketone O-oxide: spectroscopic characterization, conformation, and reaction modes: OH formation and OH capture.

Dimesitylketone O-oxide 1b was synthesized by photolysis of dimesityldiazomethane dissolved in an oxygen saturated CCl3F solution at 140 K. Conformation and geometry of 1b were determined by comparing measured NMR chemical shifts with the corresponding chemical shifts calculated at the DFT-IGLO level of theory where it had to be considered that the molecule exists in two enantiomeric forms. Measured and calculated 1H chemical shifts agree within 0.

Phototoxicity of some novel porphyrin hybrids against the human leukemic cell line TF-1.

Photodynamic induced cytotoxicity by porphyrin-DNA cross linker/intercalator hybrid diads and triads has been studied on the human leukemic cell line TF-1. Cells were incubated for 1 to 4 h with these new photosensitizers and irradiated with white light. Cell survival was assessed by the propidium iodide staining, using flow cytometry analysis.