Diversity-Oriented Synthesis of 3-Iodochromones and Heteroatom Analogues via ICl-Induced Cyclization
作者:Chengxiang Zhou、Anton V. Dubrovsky、Richard C. Larock
DOI:10.1021/jo0523722
日期:2006.2.1
The ICl-inducedcyclization of heteroatom-substituted alkynones provides a simple, highly efficient approach to various 3-iodochromones and analogues. This process is run under mild conditions, tolerates various functional groups, and generally provides chromones in good to excellent yields. Subsequent palladium-catalyzed transformations afford a rapid increase in molecular complexity and a convenient
Copper-FreeSonogashira Coupling of Acid Chlorides with Terminal Alkynes in the Presence of a Reusable Palladium Catalyst: An Improved Synthesis of 3-Iodochromenones (=3-Iodo-4H-1-benzopyran-4-ones)
作者:Pravin R. Likhar、M. S. Subhas、Moumita Roy、Sarabindu Roy、M. Lakshmi Kantam
DOI:10.1002/hlca.200890032
日期:2008.2
Pd/C is used as an efficient catalyst for the copper-free Sonogashira coupling of acidchlorides and terminalalkynes to afford ynones in high yields (Tables 1 and 3). Cyclization of (2-methoxyaryl)-substituted ynones induced by I2/ammonium cerium(IV) nitrate (CAN) at room temperature gave 3-iodochromenones (=3-iodo-4H-1-benzopyran-4-ones) in excellent yield (Table 4).
Pd / C用作酰基氯与末端炔烃的无铜Sonogashira偶联的有效催化剂,可高产率提供炔酮(表1和3)。在室温下,由I 2 /硝酸铈(IV)铵(CAN)诱导的(2-甲氧基芳基)取代的炔酮的环化反应得到极好的3-碘代色酮(= 3-碘代-4 H -1-苯并吡喃-4-酮)产量(表4)。
Palladium-, ligand-, and solvent-free synthesis of ynones by the coupling of acyl chlorides and terminal alkynes in the presence of a reusable copper nanoparticle catalyst
作者:Weijiang Sun、Yan Wang、Xuan Wu、Xiaoquan Yao
DOI:10.1039/c3gc40980e
日期:——
Supported copper nanoparticles are utilized for the first time as a highly efficient and reusable catalyst in the coupling of acylchlorides and terminalalkynes to prepare various ynones. The reaction is carried out underpalladium-, ligand-, and solvent-freeconditions. The catalyst can be simply recovered and reused several times without significant loss in catalytic activity.
formation of functionalized isoxazoles and chromones, respectively. Alkoxy(aryl)methyl group containing compounds were obtained in good and high yields. An oxocarbenium ion mediated cyclization of (Z)-1,3-diarylprop-2-yn-1-one O-methyloximes and 3-arylprop-2-yn-1-(2-methoxyphenyl)-1-ones resulted in regioselective formation of functionalized isoxazoles and chromones, respectively. Alkoxy(aryl)methyl group
One-Pot Domino Friedel–Crafts Acylation/Annulation between Alkynes and 2-Methoxybenzoyl Chlorides: Synthesis of 2,3-Disubstituted Chromen-4-one Derivatives
作者:Radha Bam、Wesley A. Chalifoux
DOI:10.1021/acs.joc.8b01357
日期:2018.9.7
regioselective synthesis of 2,3-disubstituted chromen-4-one derivatives is accomplished from readily available internal alkynes and 2-methoxybenzoyl chlorides. The reaction proceeds via a domino intermolecular Friedel–Crafts acylation/intramolecular vinyl carbocation trapping (or oxa-Michael addition)/demethylation reaction sequence. This Lewis acid promoted method features relatively mild reaction conditions