[3, 3]‐Sigmatropic Rearrangement Step in the Gold‐Catalyzed Cyclization of Allyl‐(ortho‐alkinylphenyl)methyl Ethers. Issue 8 (31st May 2013)

• Record Type: Journal Article
• Authors: Ackermann, Martin; Bucher, Janina; Rappold, Melissa; Graf, Katharina; Rominger, Frank; Hashmi, A. Stephen K.
• Is Part Of: Chemistry, an Asian journal. Volume 8:Issue 8(2013:Aug.)
• Page Start: 1786
• Page End: 1794
• Publication Date: 2013-05-31
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201300324
• Languages: English
• ISSNs: 1861-4728

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The gold‐catalyzed conversion of allyl‐(<italic>ortho</italic>‐alkynylphenyl)methyl ethers was investigated, and allylated isochromenes were obtained. An optimization of the <named-content id="d288e3482" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">catalysis</named-content> conditions with respect to different phosphane and carbene ligands on gold, different counterions, and different solvents was conducted. Subsequently, the scope and limitations of this reaction were investigated with 21 substrates. The mechanistic studies show an allylic <named-content id="d288e3485" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">inversion</named-content>, as supported by NMR data and an X‐ray crystal structure analysis, as well as an <named-content id="d288e3488" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">intermolecular</named-content> reaction, as determined by crossover experiments. There is no competition of protodeauration even in the presence of water. All these observations differ from other related conversions and clearly indicate product formation by a [3, 3]sigmatropic <named-content id="d288e3491" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">rearrangement</named-content> in the step forming the new CC bond.</p> </abstract>