The palladium-catalyzed reaction of γ-silylated allyl acetates with water in the presence of CsF induces a previously unprecedented 1,2-shift of a substituent on silicon to produce allylsilanes in situ. The catalytic activity of the palladium increased when using an electron-poor phosphine ligand possessing fluorinated substituents. Further investigation of the reaction revealed that the approximate
Alkene Isomerization-Hydroarylation Tandem Catalysis: Indole C2-Alkylation with Aryl-Substituted Alkenes Leading to 1,1-Diarylalkanes
作者:Takeshi Yamakawa、Naohiko Yoshikai
DOI:10.1002/asia.201400135
日期:2014.5
with nonconjugated arylalkenes through a tandem alkene isomerization–hydroarylation process, affording 1,1‐diarylalkanes with exclusive regioselectivity. The feasibility of the tandem catalysis was demonstrated for allyl‐, homoallyl‐, and bishomoallylbenzene derivatives. The catalytic system is also applicable to a variety of β‐substituted styrene derivatives. Mechanistic experiments using deuterium‐labeled
Reactions of Polymer-Supported α-Selenoaldehydes with Grignard Regents. A Facile Solid-Phase Stereoselective Synthesis of (<i>E</i>)-1,2-Disubstituted Ethenes
作者:Shou-Ri Sheng、Xian Huang
DOI:10.1002/jccs.200300125
日期:2003.8
Polymer-supportedα-selenoaldehydes easily obtained by reaction of polymer-supported 4-(phenyl-seleno)morpholine with aldehydes react with Grignard reagents to form polymer-supported (3-hydroxyalkyl selenides, which were treated with thionyl chloride/triethylamine leading to (E)-1,2-disubstitutedethenes in good yields.
copper-catalyzed coupling reaction of 2-pyridinesulfonates with Grignardreagents revealed that reactions with catalytic Cu(OTf)2 were completed in <40 min. The results differed from those of the previous CuI-catalyzed reactions of tosylates in the presence of additives (LiOMe and TMEDA) for 12–24 h. It was shown that the preferred coordination of the leaving group to the reagents accelerated the reaction
The reaction between secondary Grignardreagents and alkylthioarenes or alkylthioalkenes in the presence of 1:1 nickel dichloride–triphenylphosphine causing the substitution of alkylthio-groups by hydrogen atoms, the nickel(0)-induced replacement of alkylthio-groups of the aforementioned sulphides by alkyl or aryl functions, and the observation of regiocontrol in the catalysed reactions of Grignard