Intramolecular photoinduced oxidative addition

Intramolecular photoinduced oxidative addition reactions can also occur. For example, when the platinum(0) complex Pt(C2H4)(PPh3)2 is photolyzed at 280 nm, the product is a cyclometalated platinum(II) complex formed by intramolecular oxidative addition of the ortho carbon-hydrogen bond, followed by ethylene insertion into the intmnediate platinum(II) hydride ... 

Enhancement of fluorescence due to the complexation of metal ions with fluoroionophores has been used as a well-precedented technique to analyze for the presence of metal ions [189-191], A number of studies have reported chelating fluorophores whose emission spectra change upon the addition of metal ions [192-198]. One remarkable result of this emission intensity enhancement is shown in Scheme 23, where the chelation of zinc chloride to 9,10-bis(((2-(dimethylamino)ethyl)methylamino)methyl)anthracene drastically enhances the observed fluorescence by a factor greater than 1000-fold [199], In the absence of Zn2+, the singlet excited state of anthracene moiety is strongly quenched by intramolecular photoinduced electron transfer from the amine to the anthracene moiety. The complex formation of Zn2+ with the amine moiety may result in the largely positive shift of the one-electron oxidation potential. Thus, intramolecular photoinduced electron transfer is strongly suppressed by the complexation of the amine moiety with Zn2+,... 

Isomerization and polymerization reactions of alkenes and alkynes are to be expected because both the MLCT and LMCT excited states have diradical character. Both the tetracyanoethylene and dicyanoacetylene 7r-complexes of Pt(PPh3>2 undergo a photoinduced intramolecular oxidative addition reaction to give the cyano vinyl and cyano acetylide complexes of platinum(II) respectively ... 

Highly efficient and stereoselective addition of tertiary amines to electron-deficient alkenes is used by Pete et al. for the synthesis of necine bases [26,27], The photoinduced electron transfer of tertiary amines like Af-methylpyrrolidine to aromatic ketone sensitizers yield regiospecifically only one of the possible radical species which then adds diastereospecifically to (5I )-5-menthyloxy-2-(5//)-furanone as an electron-poor alkene. For the synthesis of pyrrazolidine alkaloids in approximately 30% overall yield, the group uses a second PET step for the oxidative demethylation of the pyrrolidine. The resulting secondary amine react spontaneously to the lactam by intramolecular aminolysis of the lactone (Scheme 20) [26,27]. 

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