Palladium(II)-mediated oxidative carbonylation reactions have been used to synthesize 11C-radiolabelled ureas via the coupling of amines with [11C]carbon monoxide, in a one-pot process. Following trapping of 11CO in a solution of copper(I) tris(3,5-dimethylpyrazolyl)borate, homocoupling reactions of primary aliphatic amines proceed in the presence of Pd(PPh3)2Cl2 to give the corresponding N,N-disubstituted [11C]ureas. Secondary amines do not produce the corresponding N,N,N,N-tetrasubsituted [11C]ureas under these conditions. This difference in reactivity allows for the formation of unsymmetrical N,N’,N’-trisubstituted [11C]ureas using a mixture of a primary amine and a reactive secondary amine. The potential use of this method in positron emission tomography (PET) was demonstrated by the synthesis of the M1 muscarinic acetylcholine receptor radiotracer, [11C-carbonyl]GSK1034702.
钯(II)介导的氧化羰基化反应已被用于通过将胺与[11C]
一氧化碳耦合,在一步法中合成11C放射性标记的
脲类化合物。在将11CO捕获在
铜(I)三(
3,5-二甲基吡唑)
硼酸盐溶液后,初级脂肪胺的同源偶联反应在Pd(PPh3)2Cl2的存在下进行,生成相应的N,N-二取代[11C]
脲。次级胺在这些条件下不产生相应的N,N,N,N-四取代[11C]
脲。这种反应性差异使得可以利用初级胺与反应性较强的次级胺的混合物形成不对称的N,N’,N’-三取代[11C]
脲。通过合成M1毒蕈碱型
乙酰胆碱受体放射性示踪剂[11C-羰基]GSK1034702,展示了该方法在正电子发射断层成像(PET)中的潜在应用。