Dichloroketene-Induced Cyclizations of Vinyl Sulfilimines: Application of the Method in the Synthesis of (±)-Desoxyeseroline
作者:Albert Padwa、Shinji Nara、Qiu Wang
DOI:10.1021/jo051550o
日期:2005.10.1
to yield thioalkyl-substituted γ-lactams. The overall process involves nucleophilic addition of the nitrogen atom of the sulfilimine onto the highly electrophilic dichloroketene to first generate a zwitterionic intermediate. A subsequent [3,3]-sigmatropicrearrangement is followed by intramolecular trapping of the Pummerer cation by the amido anion to furnish the observed γ-lactam product. Incorporation
Additive Pummerer reaction of heteroaromatic sulfilimines with carbon nucleophiles
作者:Albert Padwa、Shinji Nara、Qiu Wang
DOI:10.1016/j.tetlet.2005.11.026
日期:2006.1
The additive Pummerer reaction of several heteroaromatic sulfilimines has been investigated. The overall process involves the reaction of the sulfilimine with TFAA to produce a transient N-tosyl-N-trifluoroacetyl sulfonium ion. Nucleophilic attack at the adjacent vinyl carbon results in the ejection of the sulfonamide group and the resulting thionium, ion loses a proton to give the observed product. (c) 2005 Elsevier Ltd. All rights reserved.
A New Synthesis of γ-Lactams Based on the Reaction of Vinyl Sulfilimines with Dichloroketene
作者:Qiu Wang、Shinji Nara、Albert Padwa
DOI:10.1021/ol047453j
日期:2005.3.1
The reactions of several aryl-, furanyl-, and vinyl substituted sulfilimines with dichloroketene proceeded at 25 degrees C to yield thioalkyl substituted gamma-lactams which, in turn, were converted to a variety of nitrogen-containing substrates. [reaction: see text]