Carbohydrates as chiral auxiliaries: synthesis of 2-hydroxy-β-D-glucopyranosides
摘要:
A new 2-step, 1-pot procedure for the stereoselective glycosylation of allylic alcohols with 1,2-di-O-benzoyl-beta-D-glucopyranosides to produce 2-hydroxy-beta-D-glucopyranosides has been developed. The required precursor for the glycosylation was readily obtained from tri-O-benzyl-D-glucal in 2 steps (91% overall).
Novel Reactions of Ethylene Acetals with Silyl-Substituted Nucleophiles. A Mild and Efficient Procedure for the Synthesis of Homoallyl Alkyl Ethers and Unsymmetrical Dialkyl Ethers
作者:Takeshi Suzuki、Takeshi Oriyama
DOI:10.1080/00397919908086101
日期:1999.4
Abstract Efficient one-pot synthesis of homoallyl alkyl ethers and dialkyl ethers was performed by the allylation and reduction of ethyleneacetals with allyltrimethylsilane and f-butyldimethylsilane, respectively, in the presence of alkoxytrimethylsilane.
Nickel and palladium complexes of the 1,1′-bis(diphenylphosphino)ferrocene ligand effectively catalysed the regioselective cross-coupling of allylic ethers with phenylmagnesium bromide; use of the nickel catalyst leads to carbon–carbon bond formation giving the terminal alkene while the palladium catalyst gives the non-terminal alkene.
Main Group-Catalyzed Cationic Claisen Rearrangements via Vinyl Carbocations
作者:Chloe G. Williams、Sepand K. Nistanaki、Krista Dong、Woojin Lee、Kendall N. Houk、Hosea M. Nelson
DOI:10.1021/acs.orglett.4c00837
日期:2024.6.14
interception of vinyl carbocations with allylethers. The reaction utilizes commercially available borate salts as catalysts and is effective at constructing sterically hindered C–C bonds. The reaction mechanism is studied experimentally and computationally to support a charge-accelerated [3,3] rearrangement of a silyloxonium cation. Our reaction is also applied to the highlystereoselectivesynthesis of fully
The catalytic Friedel–Crafts alkylation reaction of aromatic compounds with benzyl or allyl silyl ethers using Cl2Si(OTf)2 or Hf(OTf)4
作者:Isamu Shiina、Masahiko Suzuki
DOI:10.1016/s0040-4039(02)01376-x
日期:2002.9
The Friedel-Crafts alkylation reaction of various aromatic compounds with benzyl or allyl silyl ethers is effectively promoted under mild reaction conditions using Lewis acid catalysts. A mixture of the desired phenyltolylmethanes is obtained in 80% yield from toluene with benzyl dimethylsilyl or trimethylsilyl ether at 50degreesC in the presence of a catalytic amount of Cl2Si(OTf)(2) or Hf(OTf)(2). (C) 2002 Elsevier Science Ltd. All rights reserved.