Photoinduced reactions. 169. Photochemistry of 5- and 6-iodouracils in the presence of alylsilanes and alkenes. A convenient route to (C5)- and (C6)-substituted uracils
Practical synthesis of 6-aryluridines via palladium(II) acetate catalyzed Suzuki–Miyaura cross-coupling reaction
作者:Yu-Chiao Shih、Tun-Cheng Chien
DOI:10.1016/j.tet.2011.03.051
日期:2011.5
Sugar-protected 6-halouridine derivatives underwent Suzuki–Miyaura cross-coupling reactions with arylboronic acids in the presence of palladium(II) acetate as a catalyst, triphenylphosphine as a ligand, and sodium carbonate as a base. This methodology is applicable to both the C5- and C6-position of uridine and provides a direct access for versatile uridine derivatives.
We herein present a flexible approach for the incorporation of CF3 units into a predefined site of electron-rich alkenes that exploits the regiocontrolled introduction of an iodine handle and subsequent trifluoromethylation of the C(sp2)–I bond using fluoroform-derived “ligandless” CuCF3. The broad substrate scope and functional group tolerance together with the scalability and purity of the resulting
“Ligandless” Pentafluoroethylation of Unactivated (Hetero)aryl and Alkenyl Halides Enabled by the Controlled Self-Condensation of TMSCF<sub>3</sub>-Derived CuCF<sub>3</sub>
作者:Jordi Mestre、Sergio Castillón、Omar Boutureira
DOI:10.1021/acs.joc.9b02001
日期:2019.12.6
Pentafluoroethylation of unactivated C(sp2)-X bonds (X = I, Br) using a storable, "ligandless" CuC2F5 reagent prepared by controlled self-condensation of ready available TMSCF3-derived CuCF3 has been developed. A thorough analysis by 19F NMR and ESI-MS revealed the nature of this reagent in solution. The operational simplicity and robustness of this system enables the efficient, late-stage incorporation
已经开发出了一种可活化的,“无配体的” Cu 试剂对未活化的C(sp2)-X键(X = I,Br)进行五氟乙基化,该试剂通过可控的自发TMSCF3衍生的CuCF3的自缩合制备。通过19 F NMR和ESI-MS进行的彻底分析揭示了该试剂在溶液中的性质。该系统的操作简单性和鲁棒性使C2F5单元可以高效,后期地并入各种(杂)芳基和复杂的烯基卤化物(如糖基,核苷和核碱基)中。
Synthesis of some 5-perfluoroalkenyl derivatives of uracil
1,3-Dimethyl-5-iodouracil reacts smoothly with perfluorovinyl- (and E/Z-pentafluoropropenyl)-zinc iodides in the presence of Pd° as a catalyst yielding the appropriate 5-perfluoroalkenyl derivatives of uracil at high and moderate yield. In an analogous reaction, 1,3-dimethyl-6-iodouracils did not yield the expected coupling products.