Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes DOI Creative Commons
Phong Thai,

Lauv Patel,

Diyasha Manna

et al.

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 2305 - 2312

Published: Sept. 11, 2024

Iminoiodinanes comprise a class of hypervalent iodine reagents that is often encountered in nitrogen-group transfer (NGT) catalysis. In general, transition metal catalysts are required to effect efficient NGT unactivated olefins because iminoiodinanes insufficiently electrophilic engage direct aziridination chemistry. Here, we demonstrate 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) activates N -arylsulfonamide-derived for the metal-free olefins. 1 H NMR and cyclic voltammetry (CV) studies indicate hydrogen-bonding between HFIP iminoiodinane generates an oxidant capable Stereochemical scrambling during 1,2-disubstituted observed interpreted as evidence proceeds via carbocation intermediate subsequently cyclizes. These results simple method activating reagents, provide analysis extent activation achieved by H-bonding, potential chemical non-innocence fluorinated alcohol solvents

Language: Английский

HFIP in Organic Synthesis DOI
Hashim F. Motiwala,

Ahlam M. Armaly,

Jackson G. Cacioppo

et al.

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(15), P. 12544 - 12747

Published: July 17, 2022

1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) is a polar, strongly hydrogen bond-donating solvent that has found numerous uses in organic synthesis due to its ability stabilize ionic species, transfer protons, and engage range of other intermolecular interactions. The use this exponentially increased the past decade become choice some areas, such as C–H functionalization chemistry. In review, following brief history HFIP an overview physical properties, literature examples reactions using or additive are presented, emphasizing effect each reaction.

Language: Английский

Citations

313
Merging shuttle reactions and paired electrolysis for reversible vicinal dihalogenations DOI
Xichang Dong,

Johannes L. Roeckl,

Siegfried R. Waldvogel

et al.

Science, Journal Year: 2021, Volume and Issue: 371(6528), P. 507 - 514

Published: Jan. 28, 2021

Vicinal dibromides and dichlorides are important commodity chemicals indispensable synthetic intermediates in modern chemistry that traditionally synthesized using hazardous elemental chlorine bromine. Meanwhile, the environmental persistence of halogenated pollutants necessitates improved approaches to accelerate their remediation. Here, we introduce an electrochemically assisted shuttle (e-shuttle) paradigm for facile scalable interconversion alkenes vicinal dihalides, a class reactions can be used both synthesize useful dihalogenated molecules from simple recycle waste material through retro-dihalogenation. The reaction is demonstrated 1,2-dibromoethane, as well 1,1,1,2-tetrachloroethane or 1,2-dichloroethane, dibrominate dichlorinate, respectively, wide range setup with inexpensive graphite electrodes. Conversely, hexachlorinated persistent pollutant lindane could fully dechlorinated benzene soil samples alkene acceptors.

Language: Английский

Citations

184
Fluorination of arylboronic esters enabled by bismuth redox catalysis DOI Open Access
Oriol Planas, Feng Wang, Markus Leutzsch

et al.

Science, Journal Year: 2020, Volume and Issue: 367(6475), P. 313 - 317

Published: Jan. 17, 2020

Teaching bismuth to make and break bonds One major reason why transition metals are good catalysts is that they can shuttle between oxidation states. This flexibility lets them slide in out of chemical bonds; so, for instance, snip a bond carbon boron then stitch carbonfluorine its place. Planas et al. now report also orchestrate such bond-swapping events. They implement fully catalytic cycle fluorination aryl boronates, which hops +3 +5 Science , this issue p. 313

Language: Английский

Citations

166
Visible‐Light‐Induced Vicinal Dichlorination of Alkenes through LMCT Excitation of CuCl2 DOI

Pengcheng Lian,

Wenhao Long,

Jingjing Li

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(52), P. 23603 - 23608

Published: Sept. 14, 2020

Abstract This work demonstrates photoredox vicinal dichlorination of alkenes, based on the homolysis CuCl 2 in response to irradiation with visible light. catalysis proceeds via a ligand metal charge transfer process and provides an exciting opportunity for synthesis 1,2‐dichloride compounds using inexpensive, low‐molecular‐weight chlorine source. new exhibits wide substrate scope, excellent functional group tolerance, extraordinarily mild conditions does not require external ligands. Mechanistic studies show that ready formation atom radicals is responsible facile C−Cl bonds this synthetic process.

Language: Английский

Citations

102
Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron‐Rich Substrates DOI Creative Commons
Sayad Doobary,

Alexi T. Sedikides,

Henry P. Caldora

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(3), P. 1155 - 1160

Published: Nov. 7, 2019

Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and conformation. The oxidative difluorination of alkenes represents an strategy for their preparation, yet current methods limited alkene-types tolerance electron-rich, readily oxidized functionalities, as well safety scalability. Herein, we report a method the number unactivated that is tolerant electron-rich functionality, giving products otherwise unattainable. Key to success electrochemical generation hypervalent iodine mediator using "ex-cell" approach, which avoids substrate decomposition. more sustainable conditions give good excellent yields up decagram scales.

Language: Английский

Citations

101
Expanding organofluorine chemical space: the design of chiral fluorinated isosteres enabled by I(i)/I(iii) catalysis DOI Creative Commons

Stephanie Meyer,

Joel Häfliger, Ryan Gilmour

et al.

Chemical Science, Journal Year: 2021, Volume and Issue: 12(32), P. 10686 - 10695

Published: Jan. 1, 2021

Short aliphatic groups are prevalent in bioactive small molecules and play an essential role regulating physicochemistry molecular recognition phenomena.

Language: Английский

Citations

56
Difunctionalization Processes Enabled by Hexafluoroisopropanol DOI Creative Commons
Maciej Piejko, Joseph Moran, David Lebœuf

et al.

ACS Organic & Inorganic Au, Journal Year: 2024, Volume and Issue: 4(3), P. 287 - 300

Published: March 4, 2024

In the past 5 years, hexafluoroisopropanol (HFIP) has been used as a unique solvent or additive to enable challenging transformations through substrate activation and stabilization of reactive intermediates. this Review, we aim at describing difunctionalization processes which were unlocked when HFIP was involved. Specifically, focus on cyclizations additions alkenes, alkynes, epoxides, carbonyls that introduce wide range functional groups interest.

Language: Английский

Citations

14
Enantioselective Synthesis of 3‐Fluorochromanes via Iodine(I)/Iodine(III) Catalysis DOI Creative Commons

Jérôme C. Sarie,

Christian Thiehoff,

Jessica Neufeld

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(35), P. 15069 - 15075

Published: April 29, 2020

The chromane nucleus is common to a plenum of bioactive small molecules where it frequently oxidized at position 3. Motivated by the importance this in conferring efficacy, and prominence bioisosterism drug discovery, an iodine(I)/iodine(III) catalysis strategy access enantioenriched 3-fluorochromanes disclosed (up 7:93 e.r.). In situ generation ArIF2 enables direct fluorocyclization allyl phenyl ethers generate novel scaffolds that manifest stereoelectronic gauche effect. Mechanistic interrogation using deuterated probes confirms stereospecific process consistent with type IIinv pathway.

Language: Английский

Citations

62
A Chiral Pentafluorinated Isopropyl Group via Iodine(I)/(III) Catalysis DOI Creative Commons

Stephanie Meyer,

Joel Häfliger,

Michael Schäfer

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(12), P. 6430 - 6434

Published: Jan. 15, 2021

An I(I)/(III) catalysis strategy to construct an enantioenriched fluorinated isostere of the

Language: Английский

Citations

49
Organoiodine-Catalyzed Enantioselective Intermolecular Oxyamination of Alkenes DOI

Chisato Wata,

Takuya Hashimoto

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(4), P. 1745 - 1751

Published: Jan. 22, 2021

Metal-free, catalytic enantioselective intermolecular oxyamination of alkenes is realized by use organoiodine(I/III) chemistry. The protocol applicable toward aryl- and alkyl-substituted with high enantioselectivity electronically controlled regioselectivity. oxyaminated products can be easily deprotected in one step to reveal free amino alcohols yields without loss enantioselectivity. A key our success the discovery a virtually unexplored chemical entity, N-(fluorosulfonyl)carbamate, as bifunctional N,O-nucleophile.

Language: Английский

Citations

46