On the basis of ab initio calculations we propose a revised mechanism for the reaction of organic sulfides with singlet oxygen, which is more consistent with experimental evidence than previous schemes. In aprotic solvents the reagents initially form a weakly bound peroxysulfoxide, with a small barrier due to entropy. The peroxysulfoxide may decay back to ground state (triplet) oxygen, be trapp...

UNLABELLED Translation of new methodologies for labeling nonactivated aromatic molecules with (18)F remains a challenge. Here, we report a one-step, regioselective, metal-free (18)F-labeling method that uses a hypervalent iodonium(III) ylide precursor, to prepare the radiopharmaceutical (18)F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile ((18)F-FPEB). METHODS Automated radiosynthesis of (18)...

Improved photo-labile protecting groups, with high sensitivity to two-photon excitation, are needed for the controlled release of drugs, as tools in neuroscience and physiology. Here we present a new modular approach to the design of caging groups based on photoinduced electron transfer from an electron-rich two-photon dye to an electron acceptor, followed by scission of an ester to release a c...

The title compound, C21H21NO, is a vinyl-ogous amide (enaminone) produced by reaction of 1-(2-phenyl-prop-2-en-1-yl)pyrrolidine-2-thione with phenacyl bromide. In the mol-ecule, the phenyl rings are twisted from the mean plane of the pyrrolidine ring by 11.2 (1) and 67.3 (1)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules related by translation along the b axis into chains.

The reaction of readily available imidazolium–phosphonium salt [MesIm(CH2)3PPh3](OTf)2 with PdCl2 in the presence an excess Cs2CO3 afforded selectively one step cationic Pd(II) complex [(C,C,C)Pd(NCMe)](OTf) exhibiting LX2-type NHC-ylide-aryl C,C,C-pincer ligand via formal triple C–H bond activation. replacement labile MeCN latter by CNtBu and CO fragments allowed to estimate overall electronic...

A stereocontrolled synthesis of norphenyl hyperolactone C together with its utility as a direct precursor to the anti-HIV agent hyperolactone C and analogues by addition of organolithiums, are described. Preliminary studies to access this key building block in a catalytic enantioselective manner are also reported.

The Wittig reaction and its variants are the most powerful approaches for constructing carbon-carbon double bonds in organic synthesis due to their unambiguous positioning and good stereoselectivity.1 Of the recent developments,2-4 much attention has been paid to ylide olefination of aldehydes3 and ketones4 under neutral conditions by transition metal complex-catalyzed decomposition of diazo co...

the reaction between ni(ii), co(ii), cr(iii) bitrates, ni(ii) chloride and ambidentate a-keto ylide benzoylmethylenetriphenylphosphine (bppy) resulted in isolation of [ni(bppy)2](no3)2.2h2o, [ni(bppy)2]cl2, [co(bppy)2](no3)2 and [cr(bppy)3](no3)3; 2h2o. the compounds were characterized by elemental analyses and infrared 1hnmr spectroscopy, molar conductivity in solution and molecular weight mea...