Studies of hydrogen isotope scrambling during the dehalogenation of aromatic chloro-compounds with deuterium gas over palladium catalysts.,Journal of Labelled Compounds and Radiopharmaceuticals

当前位置： X-MOL 学术 › J. Label. Comp. Radiopharm. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Studies of hydrogen isotope scrambling during the dehalogenation of aromatic chloro-compounds with deuterium gas over palladium catalysts.
Journal of Labelled Compounds and Radiopharmaceuticals ( IF 0.9 ) Pub Date : 2020-09-04 , DOI: 10.1002/jlcr.3878
William J S Lockley ₁ , Niccolò A E Venanzi ₂ , Georgie J Crane ₁

Affiliation

Catalytic dehalogenation of aromatic halides using isotopic hydrogen gas is an important strategy for labelling pharmaceuticals, biochemicals, environmental agents and so forth. To extend, improve and further understand this process, studies have been carried out on the scrambling of deuterium isotope with protium during the catalytic deuterodehalogenation of model aryl chlorides using deuterium gas and a palladium on carbon catalyst in tetrahydrofuran solution. The degree of scrambling was greatest with electron‐rich chloroarene rings. The tetrahydrofuran solvent and the triethylamine base were not the source of the undesired protium; instead, it arose, substantially, from the water content of the catalyst, though other sources of protium may also be present on the catalyst. Replacement of the Pd/C catalyst with one prepared in situ by reduction of palladium trifluoroacetate with deuterium gas and dispersed upon micronised polytetrafluoroethylene led to much reduced scrambling (typically 0–6% compared with up to 40% for palladium on carbon) and to high atom% abundance, regiospecific labelling. The improved catalytic system now enables efficient polydeuteration via the dehalogenation of polyhalogenated precursors, making the procedure viable for the preparation of MS internal standards and, potentially, for high specific activity tritium labelling.

中文翻译：

钯催化剂上氘气芳香氯代化合物脱卤过程中氢同位素扰乱的研究。

使用同位素氢气催化芳香卤化物脱卤是标记药物、生物化学品、环境制剂等的重要策略。为了扩展、改进和进一步理解这一过程，在四氢呋喃溶液中使用氘气和钯碳催化剂对模型芳基氯进行催化氘代脱卤过程中，对氘同位素与氕的置乱进行了研究。富含电子的氯芳烃环的扰乱程度最大。四氢呋喃溶剂和三乙胺碱不是不需要的氕的来源；相反，它基本上是由催化剂的水含量产生的，尽管催化剂上也可能存在其他来源的氕。用通过氘气还原三氟乙酸钯并分散在微粉化聚四氟乙烯上而原位制备的 Pd/C 催化剂代替 Pd/C 催化剂，可以大大减少扰乱（通常为 0-6%，而碳载钯高达 40%），并提高原子丰度、区域特异性标记。改进的催化系统现在可以通过多卤化前体的脱卤来实现高效的聚氘化，从而使该程序可用于制备 MS 内标，并有可能用于高比活度氚标记。

更新日期：2020-11-03

点击分享查看原文

点击收藏

阅读更多本刊最新论文