Potential kinetic control of ultrasonic 1H→ 2H isotopic exchange by transition metal doping of Raney–nickel® catalysts

• Published in: Tetrahedron letters Vol. 43; no. 49; pp. 8985 - 8987
• Main Authors: Cioffi, Eugene A., Alston, Kristen E., Patel, Ami M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2002
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/S0040-4039(02)02185-8

Raney-nickel®-catalyzed 1H→ 2H isotopic exchange in non-reducing carbohydrates is conducted under mild conditions using ultrasonic irradiation. The initial and overall rates of isotopic exchange are modulated by the presence of transition metals, either in the initial alloy melt or subsequently plated onto the digested catalyst. Only the Raney-nickel® type alloys afforded stereospecific C– 1H→C– 2H isotopic exchange in an ultrasonic field. Typical supported precious metal catalysts, supported Ni catalysts, singular metal catalysts, or multi-phasic catalysts were either totally ineffective or caused substrate decomposition. Raney-nickel®-catalyzed 1H→ 2H isotopic exchange rates are modulated by the presence of transition metals. Other typical hydrogenation catalysts were ineffective or caused product decomposition. Only Ni containing Raney®-type catalysts are effective.