Efficient Transesterification/Acylation Reactions Mediated by <i>N</i>-Heterocyclic Carbene Catalysts
作者:Gabriela A. Grasa、Tatyana Güveli、Rohit Singh、Steven P. Nolan
DOI:10.1021/jo0267551
日期:2003.4.1
Imidazol-2-ylidenes, a family of N-heterocyclic carbenes (NHC), are efficient catalysts in the transesterification involving numerous esters and alcohols. Low catalyst loadings of aryl- or alkyl-substituted NHC catalysts mediate the acylation of alcohols with enol acetates in short reaction times at room temperature. Commercially available and more difficult to cleave methyl esters react with primary
Regiochemical Control in the Metal-Catalyzed Transposition of Allylic Silyl Ethers
作者:Eric C. Hansen、Daesung Lee
DOI:10.1021/ja0620639
日期:2006.6.1
A novel mode of regiochemical control over the allylic [1,3]-transposition of silyloxy groups catalyzed by Re2O7 has been developed. This strategy relies on a cis-oriented vinyl boronate, generated from the Alder-ene reaction of homoallylic silyl ethers and alkynyl boronates, to trap out the allylic hydroxyl group. The resulting cyclic boronic acids are excellent partners for cross-coupling reactions
Total Synthesis and Proof of Relative Stereochemistry of (−)-Aureonitol
作者:Peter J. Jervis、Liam R. Cox
DOI:10.1021/jo801338t
日期:2008.10.3
Two trisubstituted epimeric tetrahydrofurans, 1 and 2, have been synthesized in order to confirm the relative stereochemistry in the natural product aureonitol. The key step in the synthesis of 1 and 2 involved a stereoselective intramolecular allylation of an allylsilane with an aldehyde, which introduced the stereotriad in the five-membered ring. The major tetrahydrofuran diastereoisomer 18 from
Acetal compound, polymer, resist composition and patterning response
申请人:Shin-Etsu Chemical Co., Ltd.
公开号:US20020132970A1
公开(公告)日:2002-09-19
Acetal compounds in which a 5- or 6-membered ring acetal structure is connected to a norbornene structure through a linker represented by —(CH
2
)
m
— in which one hydrogen atom may be substituted with a hydroxyl or acetoxy group, and m is from 1 to 8 are novel. Using the acetal compounds as a monomer, polymers are obtained. A resist composition comprising the polymer as a base resin is sensitive to high-energy radiation and has excellent sensitivity, resolution, and etching resistance.
Polyhydroxyalkanoic Acid Having Vinyl, Ester, Carboxyl or Sulfonic Acid Group and Producing Method Therefor
申请人:Kenmoku Takashi
公开号:US20080064828A1
公开(公告)日:2008-03-13
The invention is to provide a novel polyhydroxyalkanoate having a reactive function group within the molecule and a producing method therefor In a polyhydroxyalkanoate containing a unit having a vinyl group in a side chain, such vinyl group is utilized for deriving a polyhydroxyalkanoate comprising a carboxyl group or a unit having an amide group and a sulfonic acid group.