Copper-Catalyzed Intramolecular Tandem Reaction of (2-Halogenphenyl)(3-phenyloxiran-2-yl)methanones: Synthesis of (<i>Z</i>)-Aurones
作者:Yiyi Weng、Qixu Chen、Weike Su
DOI:10.1021/jo500483u
日期:2014.5.2
A convenient and efficient method for the copper-catalyzed synthesis of (Z)-aurones via intramolecular tandem reaction of (2-halogenphenyl)(3-phenyloxiran-2-yl)methanones is reported. Moreover, a plausible mechanism for the formation of (Z)-aurones is proposed. This is the first report on the synthesis of (Z)-aurones throughcopper-catalyzedUllmanncoupling reaction employing epoxides as substrates
Transition-metal-free synthesis of polysubstituted pyrrole derivatives <i>via</i> cyclization of methyl isocyanoacetate with aurone analogues
作者:Zhi-Peng Wang、Yun He、Pan-Lin Shao
DOI:10.1039/c8ob01558a
日期:——
Presented herein is an unprecedented transition-metal-free cyclization of methyl isocyanoacetate with aurone analogues catalyzed by NaOH. Various 2,3,4-trisubstituted pyrroles were obtained in excellent yields (up to 99%). The high efficiency of this synthetic procedure, coupled with the operational simplicity and atom economy, makes it an attractive method for the synthesis of polysubstituted pyrroles
Catalytic Asymmetric [3 + 2] Cycloaddition Reaction between Aurones and Isocyanoacetates: Access to Spiropyrrolines via Silver Catalysis
作者:Zhi-Peng Wang、Sichuan Xiang、Pan-Lin Shao、Yun He
DOI:10.1021/acs.joc.8b01622
日期:2018.9.21
The first enantioselective formal [3 + 2] cycloaddition of aurone analogues with isocyanoacetates was developed via chiral Ag-complex catalysis. A variety of optically enriched spiro-1-pyrrolines were obtained in excellent yields, diastero- and enantioselectivities (up to 99% yield, >20:1 dr, >99% ee). This synthetic approach represents an extremely simple, efficient, and atom-economical method for
Attempts to prepare azido-substituted aurones via a copper-catalyzed azidation failed to afford the desired product, but instead resulted in an unusual triazole formation reaction. Further efforts noted that copper was not required for this reaction, but simply thermal treatment with sodium azide in a polar aprotic solvent. A wide range of substitution patterns were tolerated in this reaction to afford
An Efficient Synthesis of Aurone Derivatives by the Tributylphosphine-catalyzed Regioselective Cyclization of <i>o</i>-Alkynoylphenols
作者:Koya Saito、Masahito Yoshida、Takayuki Doi
DOI:10.1246/cl.140910
日期:2015.2.5
An organocatalytic regioselective synthesis of aurones from o-alkynoylphenols was achieved. A catalytic amount of tributylphosphine selectively induced the 5-exo cyclization of o-alkynoylphenols under ambient conditions leading to aurone derivatives in high to excellent yields.