Metal-Free Enantioselective Oxidative Arylation of Alkenes: Hypervalent-Iodine-Promoted Oxidative C−C Bond Formation

2016 ◽  
Vol 55 (51) ◽  
pp. 15797-15801 ◽  
Author(s):  
Mio Shimogaki ◽  
Morifumi Fujita ◽  
Takashi Sugimura
Keyword(s):  
Bond Formation ◽  
Hypervalent Iodine ◽  
Metal Free

Formation of Carbon-Oxygen Bond Mediated by Hypervalent Iodine Reagents Under Metal-free Conditions

2020 ◽  
Vol 17 ◽  
Author(s):  
Ayesha Jalil ◽  
Yaxin O Yang ◽  
Zhendong Chen ◽  
Rongxuan Jia ◽  
Tianhao Bi ◽  
...  
Keyword(s):  
Natural Products ◽  
Bond Formation ◽  
Building Blocks ◽  
Review Article ◽  
Hypervalent Iodine ◽  
Metal Free ◽  
Bioactive Natural Products ◽  
The Past ◽  
Oxygen Bond ◽  
Privileged Scaffolds

: Hypervalent iodine reagents are a class of non-metallic oxidants have been widely used in the construction of several sorts of bond formations. This surging interest in hypervalent iodine reagents is essentially due to their very useful oxidizing properties, combined with their benign environmental character and commercial availability from the past few decades ago. Furthermore, these hypervalent iodine reagents have been used in the construction of many significant building blocks and privileged scaffolds of bioactive natural products. The purpose of writing this review article is to explore all the transformations in which carbon-oxygen bond formation occurred by using hypervalent iodine reagents under metal-free conditions

Metal-Free Enantioselective Oxidative Arylation of Alkenes: Hypervalent-Iodine-Promoted Oxidative C−C Bond Formation

2016 ◽  
Vol 128 (51) ◽  
pp. 16029-16033 ◽  
Author(s):  
Mio Shimogaki ◽  
Morifumi Fujita ◽  
Takashi Sugimura
Keyword(s):  
Bond Formation ◽  
Hypervalent Iodine ◽  
Metal Free

Synthesis of Isoxazolines and Isoxazoles via Metal-Free Desulfitative Cyclization

Synthesis ◽  
2018 ◽  
Vol 50 (12) ◽  
pp. 2385-2393 ◽  
Author(s):  
Qiu Sun ◽  
Ling He ◽  
Jiaxin Cheng ◽  
Ze Yang ◽  
Yuansheng Li ◽  
...  
Keyword(s):  
Bond Formation ◽  
Reaction System ◽  
Hypervalent Iodine ◽  
Cascade Process ◽  
One Pot ◽  
Metal Free

A novel, one-pot reaction for the synthesis of isoxazolines and isoxazoles is developed via a cascade process under metal-free conditions. The approach involves the formation of intramolecular C–N and C–O bonds and intermolecular C–C bonds from aromatic alkenes or alkynes and N-hydroxysulfonamides using hypervalent iodine(VII) and iodine as the oxidant. Activation of C–H and C–C bonds/construction of C–O bonds/elimination of SO2/C–N bond formation is achieved in sequence­ in the reaction system.

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.

Metal-free approach for hindered amide-bond formation with hypervalent iodine(iii) reagents: application to hindered peptide synthesis

2021 ◽  
Author(s):  
Hyo-Jun Lee ◽  
Xiao Huang ◽  
Shigeyoshi Sakaki ◽  
Keiji Maruoka
Keyword(s):  
Peptide Synthesis ◽  
Hydrogen Fluoride ◽  
Bond Formation ◽  
Amide Bond ◽  
Hypervalent Iodine ◽  
Fluoride Complex ◽  
Metal Free ◽  
Amino Esters ◽  
Amide Bond Formation

A new, bulky amide and peptide synthesis with hypervalent iodine(iii) reagent/pyridine–hydrogen fluoride complex under mild and metal-free conditions was developed by using α-amino esters with potential activating group (PAG) at the ester residue.

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.

Stereodivergent Alkyne Hydrofluorination Using a Simple Practical Reagent

2020 ◽  
Author(s):  
Rui Guo ◽  
Xiaotian Qi ◽  
Hengye Xiang ◽  
Paul Geaneoates ◽  
Ruihan Wang ◽  
...  
Keyword(s):  
Bond Formation ◽  
Biologically Active ◽  
Dft Studies ◽  
Thermodynamic Control ◽  
Important Goal ◽  
Peptide Bonds ◽  
Metal Free ◽  
Vinyl Cation ◽  
E And Z Isomers ◽  
Vinyl Fluorides

Vinyl fluorides play an important role in drug development as they serve as bioisosteres for peptide bonds and are found in a range of biologically active molecules. The discovery of safe, general and practical procedures to prepare vinyl fluorides remains an important goal and challenge for synthetic chemistry. Here we introduce an inexpensive and easily-handled reagent and report simple, scalable, and metal-free protocols for the regioselective and stereodivergent hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These conditions were suitable for a diverse collection of alkynes, including several highly-functionalized pharmaceutical derivatives. Mechanistic and DFT studies support C–F bond formation through a vinyl cation intermediate, with the (E)- and (Z)-hydrofluorination products forming under kinetic and thermodynamic control, respectively.<br>

Regioselective C3-H Trifluoromethylation of 2H-Indazole Under Transition-Metal-Free Photoredox Catalysis

2019 ◽  
Author(s):  
Arumugavel Murugan ◽  
Venkata Nagarjuna Babu ◽  
Nagaraj Sabarinathan ◽  
Sharada Duddu. S
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Practical Approach ◽  
Hypervalent Iodine ◽  
Radical Mechanism ◽  
Photoredox Catalysis ◽  
Metal Free

Here we report a visible-light-promoted metal-free regioselective C3-H trifluoromehtylation reaction that proceeds via radical mechanism and which supported by control experiments. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the present trifluoromethylation reaction and synthesis of a library of trifluoromethylated indazoles.

Synthesis of unsymmetrical phenylurea derivatives via oxidative cross coupling of aryl formamides with amines under metal-free conditions

2015 ◽  
Vol 39 (2) ◽  
pp. 805-809 ◽  
Author(s):  
Nagireddy Veera Reddy ◽  
Pailla Santhosh Kumar ◽  
Peddi Sudhir Reddy ◽  
Mannepalli Lakshmi Kantam ◽  
Kallu Rajender Reddy
Keyword(s):  
Cross Coupling ◽  
Hypervalent Iodine ◽  
Direct Transformation ◽  
Metal Free

A direct transformation of N-aryl formamides to the corresponding phenylurea derivatives via the formation of isocyanate intermediates is achieved in good yields using hypervalent iodine reagents as external oxidants.

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