One-step exchange-labelling of pyridines and other N-heteroaromatics using deuterium gas: catalysis by heterogeneous rhodium and ruthenium catalysts

The use of metal‐catalysed hydrogen isotope exchange in the contract supply of tritiated compounds

“…A similar type of exchange that has been used with some success is exchange into the protons a to the pyridine nitrogen, using rhodium on charcoal as catalyst, as reported in the work of Alexakis et al 9 We discovered this when attempting to fully reduce a pyridine ring with tritium gas, under forcing conditions, using rhodium on charcoal as catalyst -rather than reducing the ring, we found a fully intact aromatic ring but an exchangelabelled starting material! An example is the proprietary compound (Figure 9), partial structure showed below:…”

Die Renaissance des H/D‐Austausches

“…Die Reaktionen wurden in THF bei Raumtemperatur durchgeführt und lieferten bereits nach zwei Stunden beachtliche Werte für den Deuteriumeinbau. [130] 4.5. Nickel-katalysierter H/D-Austausch Seit den ersten, von Lauer und Errede [131] sowie von Bonner [132] entwickelten Anwendungen wurden RaneyNickel-katalysierte H/D-Austauschreaktionen vor allem für die Deuterierung aromatischer Substrate eingesetzt.…”

The effect of adding Crabtree's catalyst to rhodium black in direct hydrogen isotope exchange reactions

“…All other solvents and reagents were used as received, purchased from Sigma-Aldrich, ABCR, Fluka, Alfa Aesar and Acros. 1 H and 13 C NMR spectra were obtained on a Bruker AV600 spectrometer with a 5 mm TCI-Cryoprobe or a Bruker DRX500 spectrometer with a 5 mm PAPPI-probe. The deuterium content was measured on the basis of integration.…”

“…Recently, Alexakis et al 1 reported the use of heterogeneous systems in THF as suitable catalysts for promoting hydrogen isotope exchange in pyridines and other nitrogen heteroaromatic compounds. These catalytic systems were based on group VIII metals such as rhodium or ruthenium, used as rhodium black, rhodium on alumina or ruthenium black.…”