Studies of hydrogen isotope scrambling during the dehalogenation of aromatic chloro‐compounds with deuterium gas over palladium catalysts
作者:William J.S. Lockley、Niccolò A. E. Venanzi、Georgie J. Crane
DOI:10.1002/jlcr.3878
日期:2020.11
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
使用同位素氢气对芳族卤化物进行催化脱卤是标记药物、生物化学品、环境试剂等的重要策略。为了扩展、改进和进一步了解这一过程,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,对氘同位素与氚的扰乱进行了研究。富电子氯芳烃环的加扰程度最大。四氢呋喃溶剂和三乙胺碱不是不想要的朊的来源;相反,它主要来自催化剂的水含量,尽管其他来源的朊也可能存在于催化剂上。用一种制备的催化剂代替 Pd/C 催化剂通过用氘气原位还原三氟乙酸钯并分散在微粉化聚四氟乙烯上,可显着减少乱序(通常为 0-6%,而碳载钯最高可达 40%)和高原子百分比丰度,区域特异性标记。改进后的催化系统现在可以通过多卤化前体的脱卤实现高效的多氘化,使该过程可用于制备 MS 内标,并可能用于高比活性氚标记。
Comparison of Copper(II) Acetate Promoted N-Arylation of 5,5-Dimethyl Hydantoin and Other Imides with Triarylbismuthanes and Aryl Boronic Acids
作者:Helmut Hügel、Colin Rix、Karin Fleck
DOI:10.1055/s-2006-949638
日期:2006.9
This work demonstrates that the copper acetate promoted N-arylation of imides with boronic acids can be employed as a major method for the synthesis of N3-aryl hydantoins.
Preparation of reusable copper-based biomass-carbon aerogel catalysts and their application in highly selective reduction of maleimides to succinimides with hydrosilane as a hydrogen source
aerogel construction, and customizable carbonization was designed for the reduction of copper trifluoromethane sulfonate (Cu(OTf)2) to Cu(0) and Cu(I) on the CAC. The Cu(OTf)2@CAC exhibited excellent catalytic activity, chemo-selectivity, and recyclability for selective maleimide reduction to succinimides under mild conditions. Moreover, the Cu(OTf)2@CAC can be reused six times without noticeably losing