Tetrabutylammonium Iodide Mediated Sulfenylation of Poly­substituted 1H-Pyrazol-5-amines with Arylsulfonyl Hydrazides

Synthesis ◽  
2021 ◽  
Author(s):  
Bin Dai ◽  
Ping Liu ◽  
Jing He ◽  
Yueting Wei ◽  
Xuezhen Li
Keyword(s):  
Bond Formation ◽  
Operating Conditions ◽  
Bond Breaking ◽  
Tetrabutylammonium Iodide ◽  
Mechanistic Investigations

AbstractA TBAI-mediated sulfenylation of N,3-diaryl-1-arylsulfonyl-1H-pyrazol-5-amines with arylsulfonyl hydrazides has been established, and an expanded inventory of N,5-diaryl-4-(arylthio)-1H-pyrazol-3-amines was constructed through C–S bond formation and N–S bond breaking. Mechanistic investigations suggest thiosulfonate as a key intermediate in the sulfenylation, and the detosylation is promoted by the generated arylsulfinic acid. The method is characterized by simple operating conditions, broad substrate range as well as gram-scale reaction.

Recent Advances in Tetrabutylammonium Iodide/t-BuOOH Promoted C—N Bond Formation

2018 ◽  
Vol 38 (4) ◽  
pp. 752
Author(s):  
Yiling Huang ◽  
Wenhui Bao ◽  
Wenming Zhu ◽  
Wenting Wei
Keyword(s):  
Bond Formation ◽  
Recent Advances ◽  
Tetrabutylammonium Iodide

Cluster Preface: Silicon in Synthesis and Catalysis

Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2394-2395 ◽  
Author(s):  
Martin Oestreich
Keyword(s):  
Organic Chemistry ◽  
Asymmetric Catalysis ◽  
Research Group ◽  
Kinetic Resolution ◽  
Bond Formation ◽  
Doctoral Degree ◽  
Ion Chemistry ◽  
National University ◽  
Type C ◽  
Mechanistic Investigations

Martin Oestreich is Professor of Organic Chemistry at the Technische Universität Berlin. His appointment was supported by the Einstein Foundation Berlin. He received his diploma degree with Paul Knochel (Marburg, 1996) and his doctoral degree with Dieter Hoppe (Münster, 1999). After a two-year postdoctoral stint with Larry E. Overman ­(Irvine, 1999–2001), he completed his habilitation with Reinhard ­Brückner (Freiburg, 2001–2005) and was appointed as Professor of Organic Chemistry at the Westfälische Wilhelms-Universität Münster (2006–2011). He also held visiting positions at Cardiff University in Wales (2005) and at The Australian National University in Canberra (2010). Martin Oestreich’s research focuses on silicon in synthesis and catalysis, the theme of the present SYNLETT Cluster. His early work centered on the use of silicon-stereogenic silicon reagents in asymmetric catalysis, and his laboratory continues to employ them as stereochemical probes in mechanistic investigations. His research group made fundamental contributions to catalytic carbon–silicon bond formation with nucleo­philic and, likewise, electrophilic silicon reagents, and Martin Oestreich is probably best known for his work in silylium-ion chemistry. Recent accomplishments of his laboratory include Friedel–Crafts-type C–H silylation, transfer hydrosilylation, and kinetic resolution of alcohols by enantioselective silylation.

scholarly journals Direct C–H Alpha Arylation of Enones with ArI(O2CR)2 Reagents

2019 ◽  
Author(s):  
Felipe Cesar Sousa e Silva ◽  
Nguyen T Van ◽  
Sarah Wengryniuk
Keyword(s):  
Claisen Rearrangement ◽  
Bond Formation ◽  
Hypervalent Iodine ◽  
Enol Ethers ◽  
Silyl Enol Ethers ◽  
Metal Free ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Mechanistic Investigations

Herein, we report the metal-free direct C–H arylation of enones mediated by hypervalent iodine reagents. The reaction proceeds via a reductive iodonium Claisen rearrangement of <i>in situ </i>b-pyridinium silyl enol ethers. The aryl groups are derived from ArI(O<sub>2</sub>CCF<sub>3</sub>)<sub>2</sub> reagents, which are readily accessed from the parent iodoarenes. It is tolerant of a wide range of substitution patterns and the incorporated arenes maintain the valuable iodine functional handle. Mechanistic investigations implicate arylation via an umpoled “enolonium” species and that the presence of a b-pyridinium moiety is critical for desired C–C bond formation.

scholarly journals Bis-Phenoxo-CuII2 Complexes: Formal Aromatic Hydroxylation via Aryl-CuIII Intermediate Species

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4595
Author(s):  
Xavi Ribas ◽  
Raül Xifra ◽  
Xavier Fontrodona
Keyword(s):  
Electronic Properties ◽  
Bond Formation ◽  
Reductive Elimination ◽  
Ring Size ◽  
Coupling Reactions ◽  
Intermediate Species ◽  
Air Oxidation ◽  
Aromatic Hydroxylation ◽  
Mechanistic Investigations ◽  
Enhanced Stability

Ullmann-type copper-mediated arylC-O bond formation has attracted the attention of the catalysis and organometallic communities, although the mechanism of these copper-catalyzed coupling reactions remains a subject of debate. We have designed well-defined triazamacrocyclic-based aryl-CuIII complexes as an ideal platform to study the C-heteroatom reductive elimination step with all kinds of nucleophiles, and in this work we focus our efforts on the straightforward synthesis of phenols by using H2O as nucleophile. Seven well-defined aryl-CuIII complexes featuring different ring size and different electronic properties have been reacted with water in basic conditions to produce final bis-phenoxo-CuII2 complexes, all of which are characterized by XRD. Mechanistic investigations indicate that the reaction takes place by an initial deprotonation of the NH group coordinated to CuIII center, subsequent reductive elimination with H2O as nucleophile to form phenoxo products, and finally air oxidation of the CuI produced to form the final bis-phenoxo-CuII2 complexes, whose enhanced stability acts as a thermodynamic sink and pushes the reaction forward. Furthermore, the corresponding triazamacrocyclic-CuI complexes react with O2 to undergo 1e− oxidation to CuII and subsequent C-H activation to form aryl-CuIII species, which follow the same fate towards bis-phenoxo-CuII2 complexes. This work further highlights the ability of the triazamacrocyclic-CuIII platform to undergo aryl-OH formation by reductive elimination with basic water, and also shows the facile formation of rare bis-phenoxo-CuII2 complexes.

Sign in / Sign up

Export Citation Format

Share Document