Iodane‐Guided ortho C−H Allylation

Abstract

Ametal-free C À Hallylation strategy is described to access diverse functionalized ortho-allyl-iodoarenes.T he method employs hypervalent (diacetoxy)iodoarenes and proceeds through the iodane-guided "iodonio-Claisen" allyl transfer.T he use of allylsilanes bearing electron-withdrawing functional groups unlocks the functionalization of ab road range of substrates,i ncluding electron-neutral and electronpoor rings.T he resulting ortho-allylated iodoarenes are versatile building blocks,w ith examples of downstream transformation including ac oncise 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.