Practical metal-free synthesis of chalcone derivatives via a tandem cross-dehydrogenative-coupling/elimination reaction
作者:Yu Wei、Jinghua Tang、Xuefeng Cong、Xiaoming Zeng
DOI:10.1039/c3gc41403e
日期:——
Metal-free synthesis of chalcone derivatives through a tandem cross-dehydrogenative-coupling/eliminationreaction is described. A simple and inexpensive ammonium persulfate salt enables the reaction between ketones and benzylamines to proceed with high stereoselectivity and good functional group compatibility.
Microwave-Assisted, Aqueous Wittig Reactions: Organic-Solvent- and Protecting-Group-Free Chemoselective Synthesis of Functionalized Alkenes
作者:James McNulty、Priyabrata Das、David McLeod
DOI:10.1002/chem.201000438
日期:——
Free from protection! A general, chemoselective, protecting‐group‐ and organic‐solvent‐free route to stilbenes and heterostilbenes involving the direct synthesis of triethyl benzylic and allylic phosphonium salts from the corresponding alcohols and their microwave‐assisted, aqueous Wittig reactions is described.
Alkynes react with organoborons under a CO atmosphere in the presence of a rhodium(I) catalyst to afford mainly 5-aryl-2(5H)-furanones, α,β-unsaturated ketones, and indanones. The product selectivity can be tuned by modifying the reaction conditions.
Versatile and practical: Intermolecularhydroacylation of internalalkynes takes place in the presence of Ru catalysts together with HCO2Na and Xantphos to give the corresponding conjugated enones. Aromatic aldehydes with or without coordinating groups could be used in the present catalytic system. The solid Ru/CeO2 catalysts can be recycled for several times without significant decreases in yield
多功能和实用:内部炔烃的分子间加氢酰化反应在Ru催化剂与HCO 2 Na和Xantphos共同存在下进行,从而得到相应的共轭烯酮。具有或不具有配位基团的芳族醛可以用于本催化体系中。固体Ru / CeO 2催化剂可以循环使用几次,而收率没有明显降低(参见方案)。