Silver-promoted cross-coupling of substituted allyl(trimethyl)silanes with aryl iodides by palladium catalysis
作者:Zhen-Lin Hou、Fan Yang、Zhibing Zhou、Yu-Fei Ao、Bo Yao
DOI:10.1016/j.tetlet.2018.11.026
日期:2018.12
A ligand-free Pd-catalyzedcross-coupling of substituted allyl(trimethyl)silanes with aryl iodides enabled by silver salts was developed. This reaction delivered allylic arenes chemoselectively and regioselectively. The study suggested that the reaction might proceed through oxidative addition of ArI to Pd(0) followed by halide abstraction to give an electrophilic complex ArPdX, which further reacted
cyclopentane/[PdCl(C3H5)]2 efficiently catalyses the Heck reaction of disubstituted alkenes such as methyl crotonate, ethyl cinnamate, methyl methacrylate or α-methylstyrene with a variety of aryl halides. In the presence of 1,2-disubstituted alkenes the stereoselectivities of the reactions strongly depend on the substituents of the alkenes. Selectivities up to 97% in favor of E-isomers can be obtained
顺式,顺式,顺式-1,2,3,4-四(二苯基膦甲基)环戊烷/ [PdCl(C 3 H 5)] 2有效催化巴豆酸甲酯,肉桂酸乙酯,甲基丙烯酸甲酯或α等二取代烯烃的Heck反应-甲基苯乙烯与各种芳基卤化物。在1,2-二取代的烯烃的存在下,反应的立体选择性强烈取决于烯烃的取代基。添加到巴豆酸甲酯中可以得到高达97%的选择性,有利于E-异构体。用1,1-二取代的烯烃获得甲基丙烯酸甲酯或α-甲基苯乙烯的产物混合物。
Reaction of tertiary cyclopropyl silyl ethers with diethylaminosulfur trifluoride. Part 2: The Friedel–Crafts allylation and cyclopropylation of electron-rich aromatic compounds
The reaction of tertiary cyclopropyl silyl ethers with diethylaminosulfur trifluoride in electron-richaromaticcompounds causes the Friedel–Crafts alkylation to produce allylated or cyclopropylated aromaticcompounds.
The palladium-catalyzed synthesis of unsymmetrical 1,3-diarylpropenes from allyl esters through a Mizoroki–Heck-type reaction with aryl iodides followed by allyl cross-coupling with a variety of arylboronicacids was developed; the products are obtained in moderate to good yields by using a hydrazone–Pd(OAc)2 system.