Joseph San Filippo

The nitramine rearrangement: support of nonconcertedness from heavy-atom kinetic isotope effects

On mesure les effets isotopiques cinetiques des atomes lourds ( 14 C et 15 N) dans la formation de nitro-2-, et nitro-4 N-methyl anilines au cours de la transposition, catalysee par les acides, de la N-nitro N-methyl aniline

Thermal decomposition of n-alkyl[bis(triphenylphosphine)](carbonyl)iridium(I) complex

Abstract The decomposition of L 2 Ir(CO)R, R = n-alkyl) prepared in situ by the reacton of n-alkyllithium or -magnesium reagents with L 2 Ir(CO)Cl( 2 ) produces a mixture of n-alkane and isomerized alkene, the ratio of which is strongly dependent on the concentration [ L ] of triphenylphosphine as well as certain other additives. When [ L ] = 0, positional isomerism and isotope scrabling are extensive as is the isomerism of added olefin, suggesting that β-hydride elimination is rapid and reversible and that any olefins participating in an iridium hydride addition-elimination sequence are also capable of exchange with free olefin in solution. When [Ph 3 P]/[ 2 ] >/ 1, the principal product (>90%) is the 1-alkene. No positional isomerism or isotope scrambling is observed only a minor amount of alkane is produced. A mechanistic scheme consistent these observations is proposed.

Competition between ODD- and Even-Electron Processes

The competition between odd- and even-electron processes has been generally recognized in chemistry for many years. One of our earlier interests in this area arose in the study of the reactions of the superoxide radical anion.