Stabilized pyrrolyl iodonium salts and metal-free oxidative cross-coupling

Ohnishi, Yusuke; Koseki, Daichi; Nakamura, Akira; Dohi, Toshifumi; Kita, Yasuyuki

doi:10.1039/c6ob01764a

Cited by 33 publications

(28 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following a reported procedure, 9 potassium tertbutoxide (1.24 mg, 11.0 mmol, 1.10 equiv.) was added to a solution of 18-crown-6 ether (26.4 mg, 0.100 mmol, 10 mol%.)…”

Section: -(But-3-en-1-yl)-1h-indole (37)mentioning

confidence: 99%

“…Substrates 8a, 16 and 17 were tested under our optimized conditions ( [8][9] no product was detected.…”

Section: Control Experiments For the Indolization Of Arenes Via C-h Amentioning

confidence: 99%

“…The electrophilic character of these reagents was used for direct reactions with nucleophiles, such as alkyl lithium reagents, [7c] azides, [10a] amines [10b] and electron-rich arenes. [9] There is only one report on the use of indole iodonium salts involving a transition metal: the coppercatalyzed de-aromatization of indoles reported by You and coworkers. [11] This stands in stark contrast with the hundreds of transformations reported for other aryl iodonium salts, [6] and is probably due to the lower stability of indole and pyrrole iodonium salts in presence of metals and/or at higher temperature.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Indole‐ and Pyrrole‐BX: Bench‐Stable Hypervalent Iodine Reagents for Heterocycle Umpolung

Caramenti

Nicolai

Waser

2017

Chemistry A European J

View full text Add to dashboard Cite

Abstract:The one-step synthesis of the bench-stable hypervalent iodine reagents IndoleBX and PyrroleBX using mild Lewis acid catalyzed conditions is reported. The new reagents are stable up to 150 °C and were applied in the C-H arylation of unactivated arenes using either rhodium or ruthenium catalysts. A broad range of heterocyclic systems of high interest for synthetic and medicinal chemistry was accessed in high yields. The developed C-H functionalization could not be achieved using reported reagents or methods, highlighting the unique reactivity of Indole-and Pyrrole-BX.Pyrrole and indole heterocycles are omnipresent in natural and synthetic biologically active compounds and have found countless applications in the pharmaceutical and agrochemical industries.[1]

show abstract

“…Following a reported procedure, 9 potassium tertbutoxide (1.24 mg, 11.0 mmol, 1.10 equiv.) was added to a solution of 18-crown-6 ether (26.4 mg, 0.100 mmol, 10 mol%.)…”

Section: -(But-3-en-1-yl)-1h-indole (37)mentioning

confidence: 99%

“…Substrates 8a, 16 and 17 were tested under our optimized conditions ( [8][9] no product was detected.…”

Section: Control Experiments For the Indolization Of Arenes Via C-h Amentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Indole‐ and Pyrrole‐BX: Bench‐Stable Hypervalent Iodine Reagents for Heterocycle Umpolung

Caramenti

Nicolai

Waser

2017

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…[19] Recently,W aser has developed as ynthetic method for heteroarylbenziodoxolones from indole and relatede lectron-rich heteroarenes, andd emonstrated their utility in rhodium-or ruthenium-catalyzed directed CÀHh eteroarylation reactions. [20,21] On the other hand, (hetero)arylbenziodoxoles such as those reported here are unprecedentedi nt he literature, and their reactivity remains elusive. To explore the potential utility of these compounds, we examined severalt ransformations involvingC -I III bond cleavage (Scheme 6).…”

mentioning

confidence: 94%

Benziodoxole Triflate as a Versatile Reagent for Iodo(III)cyclization of Alkynes

Yoshikai

2017

Chemistry An Asian Journal

View full text Add to dashboard Cite

The utility of benziodoxole triflate, derived from α,α-bis(trifluoromethyl)-2-iodobenzyl alcohol, as a versatile reagent for iodo(III)cyclization via electrophilic activation of alkyne, is reported herein. The reagent promotes cyclization of alkynes tethered to a variety of nucleophilic moieties, affording benziodoxole-appended (hetero)arenes such as benzofurans, benzothiophenes, isocoumarins, indoles, and polyaromatics under mild conditions. This unprecedented class of (hetero)aryl-I compounds proved easy to purify, stable, and amenable to various synthetic transformations.

show abstract

“…Suna and coworkers reported two applications of these reagents: a Cu(I)‐catalyzed azidation in which the final product was converted in situ via click chemistry, and an amination . More stable iodonium salts were reported by Moriyama [ ][ ] and Kita and coworkers, but again, an electron‐withdrawing group on the nitrogen was required to stabilize the reagents. Imidazolyl aryliodonium salts were introduced by Shafir and co‐workers .…”

Section: Introductionmentioning

confidence: 99%

Bench‐Stable Electrophilic Indole and Pyrrole Reagents: Serendipitous Discovery and Use in C–H Functionalization

Caramenti

Waser

2017

Helvetica Chimica Acta

View full text Add to dashboard Cite

The development of reagents allowing the reversal of the standard reactivity (Umpolung) of small building blocks is an important field of research in chemistry, as it allows increasing the flexibility of organic synthesis. Indoles and pyrroles are ubiquitous heterocycles in natural products and drugs. They are usually functionalized making use of their high nucleophilicity. In contrast, only few methods are based on the use of electrophilic indole and pyrrole synthons, as the needed reagents are highly unstable or can be used only with a very narrow scope. Herein, we report the serendipitous discovery and first use in the C–H functionalization of arenes of IndoleBX and PyrroleBX, new thermally highly stable benziodoxol(on)e hypervalent iodine reagents. IndoleBX and PyrroleBX could be obtained in one step from the corresponding heterocycles and acetoxy benziodoxolone using a Lewis acid catalyst. The mild reactions conditions allowed the introduction of a broad range of functional groups, including ethers, halogens and boronic esters. The new reagents could then be used in the rhodium‐ and ruthenium‐catalyzed C–H heteroarylation of arene rings bearing heterocyclic or benzamide directing groups. Such transformations could not be realized using previously reported C–H functionalization procedures.

show abstract

Stabilized pyrrolyl iodonium salts and metal-free oxidative cross-coupling

Cited by 33 publications

References 78 publications

Indole‐ and Pyrrole‐BX: Bench‐Stable Hypervalent Iodine Reagents for Heterocycle Umpolung

Indole‐ and Pyrrole‐BX: Bench‐Stable Hypervalent Iodine Reagents for Heterocycle Umpolung

Benziodoxole Triflate as a Versatile Reagent for Iodo(III)cyclization of Alkynes

Bench‐Stable Electrophilic Indole and Pyrrole Reagents: Serendipitous Discovery and Use in C–H Functionalization

Contact Info

Product

Resources

About