Koyama S, Kumazawa Z, Kashimura N
Nucleic Acids Symp Ser. 1982(11):41-4.
Coupling reaction of 6-iodo- or 6-chloropurine with alkynes in the presence of (PPh3) 2PdCl2-CuI catalyst in triethylamine to give 6-alkynylated purines was achieved by the use of dipolar aprotic solvent as co-solvent. Under the reaction conditions, ribonucleoside as well as its tri-O-acetate of 6-chloropurine also gave the corresponding alkynylated products in high yields. Though similar reaction for 8-bromo-derivatives of adenine and guanine gave poor yields, the 8-alkynylated free bases could be obtained by acid hydrolysis of the alkynylated ribonucleosides. 6-Alkynylated purines exhibited moderate to weak cytokinin activity in Amaranthus test.
在三乙胺中，以（三苯基膦）₂氯化钯 - 碘化亚铜为催化剂，6 - 碘嘌呤或6 - 氯嘌呤与炔烃发生偶联反应生成6 - 炔基化嘌呤，该反应通过使用偶极非质子溶剂作为共溶剂得以实现。在该反应条件下，核糖核苷以及6 - 氯嘌呤的三 - O - 乙酸酯也能高产率地得到相应的炔基化产物。尽管腺嘌呤和鸟嘌呤的8 - 溴衍生物的类似反应产率较低，但通过炔基化核糖核苷的酸水解可得到8 - 炔基化游离碱。6 - 炔基化嘌呤在苋属植物试验中表现出中等至较弱的细胞分裂素活性。
