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Updated: Jul 11, 2025

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Carpe diene! Europium-catalyzed [3,3] and [5,5] rearrangements of aryl-pentadienyl ethers
Maximilian Kaiser1, Michael Steinacher1, Florian Lukas1
1Institute of Applied Synthetic Chemistry, Technische Universität Wien Getreidemarkt 9/163 1060 Wien Austria Maximilian.kaiser@tuwien.ac.at.
Abstract:
A general protocol for the europium-catalyzed rearrangement of aryl-pentadienyl-ethers is described. The mode of rearrangement and product formation in this reaction was solely determined by the aryl substituent para to the phenol. If the para-position is occupied by a substituent, the substrate undergoes a [3,3] rearrangement to the ortho-position to form a prochiral branched diene. In turn, a free para-position in the starting material allows the reaction to proceed via a [5,5] rearrangement and leads to a linear conjugated diene product. The severely underdeveloped and synthetically valuable [5,5] rearrangement was investigated in terms of scope and mechanism.
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