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Iodane‐Guided ortho C−H Allylation
Author(s) -
Chen Wei W.,
Cunillera Anton,
Chen Dandan,
Lethu Sébastien,
López de Moragas Albert,
Zhu Jun,
Solà Miquel,
Cuenca Ana B.,
Shafir Alexandr
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202009369
Subject(s) - hypervalent molecule , chemistry , sigmatropic reaction , claisen rearrangement , combinatorial chemistry , stereochemistry , organic chemistry , reagent
A metal‐free C−H allylation strategy is described to access diverse functionalized ortho ‐allyl‐iodoarenes. The method employs hypervalent (diacetoxy)iodoarenes and proceeds through the iodane‐guided “iodonio‐Claisen” allyl transfer. The use of allylsilanes bearing electron‐withdrawing functional groups unlocks the functionalization of a broad range of substrates, including electron‐neutral and electron‐poor rings. The resulting ortho ‐allylated iodoarenes are versatile building blocks, with examples of downstream transformation including a concise synthesis of the experimental antimitotic core of Dosabulin. DFT calculations shed additional light on the reaction mechanism, with notable aspects including the aromatic character of the transition‐state structure for the [3,3] sigmatropic rearrangement, as well as the highly stereoconvergent nature of the trans ‐product formation.