Deuterium isotope exchange

The kinetics of deuterium isotope exchange between diphenyl phosphine and t-butylthiol have been studied by H n.m.r. spectroscopy.274 A negative temperature coefficient was observed for the reaction of a perf1uoroalky1 phosphite with a fluorinated aldehyde.275 The kinetics for the reaction of alcohols with phosphoryl trichloride bore strong similarities to those of carboxylic acid derivatives.276 An interesting report desribed the solvolysis of ary 1 hydroxymethyl-phosphonates. It was shown that a phosphoryl group does not prevent carbocation formation on an immediately adjacent carbon atom.277... 

Curulli, A. and Slcitcr, G., Electrophilic heteroaromatic substitutions. VIII. Studies on the mechanism of the a-side-chain aminomethy-lation and hydrogen/deuterium isotope exchange reactions of a-methylpyrroles, J. Org. Chem... 50, 4925, 1985. 

Photocatalytic cyclopentane-deuterium isotopic exchange (CDIE)... 

Winger, B.E., light-Wahl, K.J., Rockwood, A.L., Smith, R.D. (1992) Probing qualitative conformation differences of mrrltiply protonated gas-phase proteins via hydrogen/deuterium isotopic exchange with DjO. Journal of the American Chemical Society, 114 (14), 5897-5898. 

A last case of sonication-sensitive catalytic reactions is the hydrogen-deuterium isotope exchange observed in carbohydrates in the presence of nickel or a nickel-aluminum alloy. A good selectivity is observed, probably due to the lower temperature allowed by sonication. However, a more complex origin can be responsible for these effects, since the sonicated alloy exhibits new features such as distinct catalytic centers, and elemental redistribution within the catalyst bulk, along with more classical consequences (surface cleaning, absence of surface area... 

Another example may be the hydrogen — deuterium isotope exchange which is assumed [187] to proceed via the H2—Hg—O2 hexagon. At least there is no doubt that the activation energy for the switching of chemical bonds in a hexagon is lower than that in a planar Hg—Dg square. 

Gupta NM, Mishra K, Belapurkar AD, et al Deuterium isotope exchange reaction between hydrogen and water over polyester-supported platinum catalysts, J Catal 121 (2) 386-395, 1990. 

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