A remote activation and metal-free transformation from alkynes to carbonyl compounds is developed. Just in the solvent of HOAc and EtOH, this reaction artfully converts alkynes to valuable ketones by...
5-<i>Endo</i>-<i>D</i><i>ig</i> Electrophilic Cyclization of 1,4-Disubstituted But-3-yn-1-ones: Regiocontrolled Synthesis of 2,5-Disubstituted 3-Bromo- and 3-Iodofurans
作者:Adam Sniady、Kraig A. Wheeler、Roman Dembinski
DOI:10.1021/ol050372i
日期:2005.4.1
[reaction: see text] 5-Endo-dig electrophiliccyclization of 1,4-diaryl but-3-yn-1-ones with N-bromosuccinimide or N-iodosuccinimide/acetone and iodine monochloride/CH(2)Cl(2), at room temperature, in the absence of base, provides 3-halo-2,5-diarylfurans with excellent regiocontrol and high yields (81-94%).
Zinc-Catalyzed Cycloisomerizations. Synthesis of Substituted Furans and Furopyrimidine Nucleosides
作者:Adam Sniady、Audrey Durham、Marco S. Morreale、Andrzej Marcinek、Slawomir Szafert、Tadeusz Lis、Krystyna R. Brzezinska、Takanori Iwasaki、Takashi Ohshima、Kazushi Mashima、Roman Dembinski
DOI:10.1021/jo8007995
日期:2008.8.1
dichloromethane at room temperature gave 2,5-di- and 2,3,5-trisubstituted furans in high yields (85−97%). DSC studies confirmed that a solely thermal process does not take place. A relevant catalytic process, employing μ-oxo-tetranuclear zinc cluster Zn4(OCOCF3)6O, yielded bicyclic furopyrimidine nucleosides, when starting from acetyl-protected 5-alkynyl-2′-deoxyuridines (85−86%). Furopyrimidine was
Room Temperature Zinc Chloride-Catalyzed Cycloisomerization of Alk-3-yn-1-ones: Synthesis of Substituted Furans
作者:Adam Sniady、Audrey Durham、Marco S. Morreale、Kraig A. Wheeler、Roman Dembinski
DOI:10.1021/ol062539t
日期:2007.3.1
[structure: see text]. 5-Endo-dig cycloisomerization of 1,4-di- and 1,2,4-trisubstituted but-3-yn-1-ones in the presence of a catalytic amount of zinc chloride (10 mol %) in dichloromethane at room temperature (22 degrees C) provides 2,5-di- and 2,3,5-trisubstituted furans in high yields (85-97%).