The emergence of sulfoxide and iodonio-based redox arylation as a synthetic tool

Shafir, Alexandr

doi:10.1016/j.tetlet.2016.05.013

Cited by 89 publications

(28 citation statements)

References 43 publications

(23 reference statements)

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“…The general preference of such reactions for electron‐rich iodoarene cores may lead in some cases to stringent scope limitation, as seen in the iodane‐directed allylation (Scheme B) . An interesting feature of these reactions is the intrinsic “safety‐catch” feature, which prevents a second C−H functionalization event but opens the door to iterative processes. The latter was recently shown for a double functionalization in a sulfoxide‐based system (Scheme E) .…”

Section: Methodsmentioning

confidence: 99%

Synthesis of Polysubstituted Iodoarenes Enabled by Iterative Iodine‐Directed para and ortho C−H Functionalization

Bouvet

Izquierdo

et al. 2018

Angew Chem Int Ed

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Among halogenated aromatics,i odoarenes are unique in their ability to produce the bench-stable halogen(III) form. Earlier,s uch iodine(III) centers were shown to enable CÀHf unctionalization ortho to iodine via halogen-centered rearrangement. The broader implications of this phenomenon are explored by testing the extent of an unusual iodane-directed para C À Hbenzylation, as well as by developing an efficient C À Hc oupling with sulfonyl-substituted allylic silanes.T hrough the combination of the one-shot nature of the coupling event and the iodine retention, multisubstituted arenes can be prepared by sequentially engaging up to three aromatic CÀH sites.T his type of iodine-based iterative synthesis will serve as atool for the formation of value-added aromatic cores.Scheme 1. Selected precedentsiniodane-and sulfoxide-directed CÀH functionalization.

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Section: Methodsmentioning

confidence: 99%

Synthesis of Polysubstituted Iodoarenes Enabled by Iterative Iodine‐Directed para and ortho C−H Functionalization

Bouvet

Izquierdo

et al. 2018

Angew Chem Int Ed

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“…The recent and rapid development of hypervalent iodine‐guided electrophilic substitutions (Scheme ) began from a series of papers by Khatri and Zhu in which they rediscovered and evaluated of the reductive iodonio‐Claisen rearrangement (RICR) RICR‐type reactions have undergone review by Shafir and also in a section of a review on C–C bond forming reactions by Hyatt et al in 2019 …”

Section: Methodsmentioning

confidence: 99%

para‐Selective Benzylation of Aryl Iodides by the in situ Preparation of ArIF₂: a Hypervalent Iodine‐Guided Electrophilic Substitution

Noorollah

Siddiqi

et al. 2020

Eur J Org Chem

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Hypervalent iodine-guided electrophilic substitution (HIGES) was described previously for the para-selective benzylation of aryl-λ 3 -iodane diacetates. One drawback of the method was the synthesis and isolation of hypervalent iodine starting materials. An improvement is reported herein in which the benzylation product can be afforded from an aryl iodide via an in situ oxidation. The metal-like properties of hypervalent iodine have been demonstrated in the transmetallation of metal-The recent and rapid development of hypervalent iodineguided electrophilic substitutions (Scheme 1) began from a series of papers by Khatri and Zhu in which they rediscovered and evaluated of the reductive iodonio-Claisen rearrangement (RICR). [1][2][3] RICR-type reactions have undergone review by Shafir and also in a section of a review on C-C bond forming reactions by Hyatt et al. in 2019. [4-6] While allylic and benzylic groups often have similarities, substituting the allyl metalloid with a benzyl metalloid in the RICR would seem to theoretical fail due to their different π-systems and the theorized Claisen-type rearrangement. [7][8][9][10][11][12] However, when the allyl metalloid was replaced by a benzyl metalloid under the RICR reaction conditions, different regioselectivity was discovered; a para-selective substitution of the aryl iodine as opposed the RICR's ortho selectivity. [13,14] The C-C bond forming methodology described herein hints at, and provides increasing evidence for, a new class of reactions involving HIGES. Elegant synthetic pathways incorporating HIGES have resulted in tetraasubstituted benzenes via four C-C bond forming reactions from iodobenzene, [13] the total synthesis of clopidogrel, [3] the total synthesis of broussin, [2] the synthesis of various heterocycles, [1] and the selective bromination of arenes. [15] DFT-calculations investigating the mechanistic aspects of RICR propargylation found an acid-activated hypervalent iodine intermediates was required. [16,17] Calculations have also shown [a]

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“…Metal‐free ortho ‐C−H functionalization of aryl iodanes has attracted great attention in the past three decades . The protocol allows for redox‐neutral cross‐coupling of ortho ‐unsubstituted aryl iodanes with certain nucleophiles through a dearomative rearrangement and deprotonative rearomatization process.…”

Section: Methodsmentioning

confidence: 99%

“…The protocol allows for redox‐neutral cross‐coupling of ortho ‐unsubstituted aryl iodanes with certain nucleophiles through a dearomative rearrangement and deprotonative rearomatization process. Inspired by the intriguing reaction pattern, we envisioned a “rearrangement/addition” sequence that may enable the dearomative dual functionalization of ortho ‐substituted aryl iodanes (Scheme e). First, a [3,3] sigmatropic rearrangement of a 2,6‐dimethyl phenyl iodane could lead to a dearomatized intermediate I that can be considered as an iodine(III)‐substituted cyclohexadiene.…”

Section: Methodsmentioning

confidence: 99%

“…Metal-free ortho-CÀHf unctionalization of aryl iodanes has attracted great attention in the past three decades. [8][9][10] Theprotocol allows for redox-neutral cross-coupling of orthounsubstituted aryl iodanes with certain nucleophiles through ad earomative rearrangement and deprotonative rearomatization process.Inspired by the intriguing reaction pattern, [8][9][10] we envisioned a"rearrangement/addition" sequence that may enable the dearomative dual functionalization of orthosubstituted aryl iodanes (Scheme 1e). First, a [ 3,3] sigmatropic rearrangement of a2 ,6-dimethyl phenyl iodane could lead to adearomatized intermediate I that can be considered as an iodine(III)-substituted cyclohexadiene.T his species should be highly electrophilic and could be readily trapped by an ucleophile to give ad ual-functionalized product.…”

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Dearomative Dual Functionalization of Aryl Iodanes

et al. 2019

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Herein we describe the dearomatization of aryl iodanes through an unprecedented “rearrangement/addition” sequence. The process consists of two stages. First, a rapid [3,3] sigmatropic rearrangement of the aryl iodane with an α‐stannyl nitrile affords a highly electrophilic dearomatized intermediate at −78 °C. A low‐temperature rearrangement then enables the unstable dearomatized species to be trapped in situ with various nucleophiles. As a consequence, the reaction not only breaks the aromaticity of the aryl iodane but also sequentially installs two different functional groups, thus resulting in a polysubstituted alicyclic product.

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The emergence of sulfoxide and iodonio-based redox arylation as a synthetic tool

Cited by 89 publications

References 43 publications

Synthesis of Polysubstituted Iodoarenes Enabled by Iterative Iodine‐Directed para and ortho C−H Functionalization

Synthesis of Polysubstituted Iodoarenes Enabled by Iterative Iodine‐Directed para and ortho C−H Functionalization

para‐Selective Benzylation of Aryl Iodides by the in situ Preparation of ArIF₂: a Hypervalent Iodine‐Guided Electrophilic Substitution

Dearomative Dual Functionalization of Aryl Iodanes

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The emergence of sulfoxide and iodonio-based redox arylation as a synthetic tool

Cited by 89 publications

References 43 publications

Synthesis of Polysubstituted Iodoarenes Enabled by Iterative Iodine‐Directed para and ortho C−H Functionalization

Synthesis of Polysubstituted Iodoarenes Enabled by Iterative Iodine‐Directed para and ortho C−H Functionalization

para‐Selective Benzylation of Aryl Iodides by the in situ Preparation of ArIF2: a Hypervalent Iodine‐Guided Electrophilic Substitution

Dearomative Dual Functionalization of Aryl Iodanes

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para‐Selective Benzylation of Aryl Iodides by the in situ Preparation of ArIF₂: a Hypervalent Iodine‐Guided Electrophilic Substitution