Preparation and Reactions of Mono- and Bis-Pivaloyloxyzinc Acetylides
作者:Carl Phillip Tüllmann、Yi-Hung Chen、Robin J. Schuster、Paul Knochel
DOI:10.1021/acs.orglett.8b01892
日期:2018.8.3
Mono-pivaloyloxyzinc acetylide and bis-pivaloyloxyzinc acetylide were selectively prepared from ethynylmagnesium bromide in quantitative yields. These zinc reagents readily underwent Negishi cross-couplings with (hetero)aryl iodides or bromides as well as subsequent Sonogashira cross-couplings. 1,3-Dipolar cycloadditions of these zinc acetylides with benzylic azides produced zincated and bis-zincated
Regioselective synthesis of functionalized 1,2,3-triazoles via oxidative [3+2]-cycloaddition using Zn(OAc)2 - tBuOOH or ZnO nanoparticle as catalyst system in aqueous medium
The regioselective synthesis of functionalized pyrazole˗1,2,3-triazoles is reported viaoxidative [3 + 2]-cycloaddition reactions of azides with β-nitrostyrenes and chalcone derivatives using Zn(OAc)2 - tBuOOH or ZnO nanoparticles as catalyst system in aqueous medium. The catalyst dependent product selectivity was observed with β-nitrostyrenes to give the triazoles with and without -NO2 group Zn(OAc)2
A Metal-Free Multicomponent Cascade Reaction for the Regiospecific Synthesis of 1,5-Disubstituted 1,2,3-Triazoles
作者:Guolin Cheng、Xiaobao Zeng、Jinhai Shen、Xuesong Wang、Xiuling Cui
DOI:10.1002/anie.201307499
日期:2013.12.9
About specifics: A method for the regiospecific synthesis of the title compounds through an unprecedented Michael addition/deacylative diazo transfer/cyclization sequence has been established. The simple and practical method can be used for the modification of primary amines including chiral α‐amines. The process involves the formation three covalent bonds and the cleavage of two covalent bonds (see
Synthesis of functionalized 1,2,3-triazoles using Bi<sub>2</sub>WO<sub>6</sub> nanoparticles as efficient and reusable heterogeneous catalyst in aqueous medium
The regioselective synthesis of functionalized triazoles is achieved using a combination of Bi2WO6 nanoparticles (10 mol%) and click conditions from β-nitrostyrenes, phenylacetylene and chalcones with azides.
Nickel-Catalyzed Azide–Alkyne Cycloaddition To Access 1,5-Disubstituted 1,2,3-Triazoles in Air and Water
作者:Woo Gyum Kim、Mi Eun Kang、Jae Bin Lee、Min Ho Jeon、Sungmin Lee、Jungha Lee、Bongseo Choi、Pedro M. S. D. Cal、Sebyung Kang、Jung-Min Kee、Gonçalo J. L. Bernardes、Jan-Uwe Rohde、Wonyoung Choe、Sung You Hong
DOI:10.1021/jacs.7b06338
日期:2017.9.6
Herein, we report a method to access 1,5-disubstituted 1,2,3-triazoles using a Cp2Ni/Xantphos catalytic system. The reaction proceeds both in water and organic solvents at room temperature. This protocol is simple and scalable with a broad substrate scope including both aliphatic and aromatic substrates. Moreover, triazoles attached with carbohydrates or amino acids are prepared via this cycloaddition