in organic synthesis and the pharmaceutical industry. The heterogeneous synthesis of nitrones with multifunctional catalysts is extremely attractive but rarely explored. Herein, we report ultrasmall platinum nanoclusters (PtNCs) encapsulated in amine‐functionalized Zr metal–organicframework (MOF), UiO‐66‐NH2 (Pt@UiO‐66‐NH2) as a multifunctional catalyst in the one‐pot tandem synthesis of nitrones
3-Thiolated 2-azetidinones: synthesis and in vitro antibacterial and antifungal activities
作者:Maaroof Zarei、Masoud Mohamadzadeh
DOI:10.1016/j.tet.2011.05.043
日期:2011.8
A series of 3-thiolated β-lactams were synthesized by [2+2] ketene–imine cycloaddition reaction from S-substituted mercaptoacetic acids and Schiff bases. Then, some of the 3-methylthio β-lactams were converted to 3-(methylsulfinyl) β-lactams and 3-(methylsulfonyl) β-lactams using m-CPBA under different reaction conditions. All the compounds were characterized by spectral data and elemental analyses
A facile and effective synthesis of 2-azetidinones via phosphonitrilic chloride
作者:Maaroof Zarei
DOI:10.1016/j.tet.2013.05.121
日期:2013.8
The Staudinger reaction of imines to β-lactams was successfully achieved with substituted acetic acid and phosphonitrilicchloride in one-pot under mild conditions. Several types of β-lactams, especially 3-electron-withdrawing group β-lactams, can be synthesized by this versatile and efficient method in good to excellent yields. This method is simple, clean, and the by-products were removed by simple
[Co(MeTAA)] Metalloradical Catalytic Route to Ketenes via Carbonylation of Carbene Radicals
作者:Andrei Chirila、Kaj M. Vliet、Nanda D. Paul、Bas Bruin
DOI:10.1002/ejic.201800101
日期:2018.6.7
Activation of these carbene precursors by the metalloradical cobalt(II) catalyst affords CoIII‐carbene radicals, which subsequently react with carbon monoxide to form ketenes. In the presence of a nucleophile (imine, alcohol, or amine) in the reaction medium the ketene is immediately trapped, resulting in the desired products in a one‐pot synthetic protocol. The β‐lactams formed upon reaction with imines
提出了一种针对 β-内酰胺、酰胺和酯的有效合成策略,包括“原位”生成烯酮并随后用亲核试剂捕获。使用廉价且高活性的钴 (II) 四甲基四氮杂 [14] 环烯催化剂 [Co(MeTAA)] 对卡宾自由基中间体进行羰基化,为取代烯酮提供了一种方便的单锅合成方案。N-甲苯磺酰腙用作卡宾前体,从而弥合醛和烯酮之间的差距。通过金属基钴 (II) 催化剂对这些卡宾前体的活化产生 CoIII-卡宾自由基,其随后与一氧化碳反应形成烯酮。在反应介质中存在亲核试剂(亚胺、醇或胺)时,乙烯酮会立即被捕获,从而在单锅合成方案中生成所需的产物。
Sterically controlled diastereoselectivity in thio-Staudinger cycloadditions of alkyl/alkenyl/aryl-substituted thioketenes
作者:Wei He、Junpeng Zhuang、Zhanhui Yang、Jiaxi Xu
DOI:10.1039/c7ob01214d
日期:——
thioketenes and imines are named as thio-Staudinger cycloadditions. The diastereoselectivity in thio-Staudinger cycloaddtions of alkyl/alkenyl/aryl-substituted thioketenes is rationalized. The steric effects of the thioketenes play an extremely important role in deciding the diastereoselectivity (cis/trans selectivity) through controlling exo- and endo-attack and subsequent ring closure. The conclusion