Cu-Catalyzed [2+2+1] Cascade Annulation of Vinyl Iodonium Salts with Element Sulfur/Selenium for the Modular Synthesis of Thiophenes and Selenophenes

2022 ◽  
Author(s):  
Yaxing Wu ◽  
Chao Wu ◽  
Fei Wang ◽  
Chao Chen
Keyword(s):  
Elemental Sulfur ◽  
Copper Salt ◽  
Iodonium Salts ◽  
Modular Synthesis

A [2+2+1] annulation protocol has been established for the modular synthesis of 2,4-disubstituted thiophenes/selenophens, with excellent regioselectivity. The reactions are catalyzed by copper salt with elemental sulfur and selenium serving...

scholarly journals Preparation and Synthetic Applicability of Novel Imidazole-Containing Cyclic Iodonium Salts

2021 ◽  
Author(s):  
Antonkin Nikita ◽  
Yulia Vlasenko ◽  
Akira Yoshimura ◽  
Vladimir Smirnov ◽  
Tatyana Borodina ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
High Reactivity ◽  
Oxidative Cyclization ◽  
The Novel ◽  
Characteristic Surface ◽  
Iodonium Salts ◽  
X Ray ◽  
Surface Features ◽  
Novel Approach ◽  
Oxidative System

<p>The novel approach to the preparation of imidazole-substituted cyclic iodonium salts has been developed via oxidative cyclization of 1-phenyl-5-iodoimidazole using cheap and available Oxone<sup>®</sup>/H<sub>2</sub>SO<sub>4</sub> oxidative system. The structure of newly prepared compounds has been proved by X-ray monocrystal diffractometry revealing the characteristic surface features for cyclic iodonium salts. The prepared compounds demonstrated the high reactivity in the heterocyclization reactions with elemental sulfur affording benzo[5,1-<i>b</i>]imidazothiazoles with good yields.</p>

scholarly journals Preparation and Synthetic Applicability of Novel Imidazole-Containing Cyclic Iodonium Salts

2021 ◽  
Author(s):  
Antonkin Nikita ◽  
Yulia Vlasenko ◽  
Akira Yoshimura ◽  
Vladimir Smirnov ◽  
Tatyana Borodina ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
High Reactivity ◽  
Oxidative Cyclization ◽  
The Novel ◽  
Characteristic Surface ◽  
Iodonium Salts ◽  
X Ray ◽  
Surface Features ◽  
Novel Approach ◽  
Oxidative System

<p>The novel approach to the preparation of imidazole-substituted cyclic iodonium salts has been developed via oxidative cyclization of 1-phenyl-5-iodoimidazole using cheap and available Oxone<sup>®</sup>/H<sub>2</sub>SO<sub>4</sub> oxidative system. The structure of newly prepared compounds has been proved by X-ray monocrystal diffractometry revealing the characteristic surface features for cyclic iodonium salts. The prepared compounds demonstrated the high reactivity in the heterocyclization reactions with elemental sulfur affording benzo[5,1-<i>b</i>]imidazothiazoles with good yields.</p>

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

One-Pot Synthesis and Conformational Analysis of 6-Membered Cyclic Iodonium Salts

2020 ◽  
Author(s):  
Lucien Caspers ◽  
Julian Spils ◽  
Mattis Damrath ◽  
Enno Lork ◽  
Boris Nachtsheim
Keyword(s):  
Conformational Analysis ◽  
Bronsted Acids ◽  
One Pot ◽  
Benzyl Alcohols ◽  
Iodonium Salts ◽  
Efficient Approach ◽  
One Pot Synthesis ◽  
Diaryliodonium Salts

In this article we describe an efficient approach for the synthesis of cyclic diaryliodonium salts. The method is based on benzyl alcohols as starting materials and consists of an Friedel-Crafts-arylation/oxidation sequence. Besides a deep optimization, particluar focusing on the choice and ratios of the utilized Bronsted-acids and oxidants, we explore the substrate scope of this transformation. We also discuss an interesting isomerism of cyclic iodonium salts substituted with aliphatic substituents at the bridge head carbon. <br>

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

2019 ◽  
Author(s):  
Evan Gardner ◽  
Caitlyn Cobb ◽  
Jeffery A. Bertke ◽  
Timothy H. Warren
Keyword(s):  
Single Crystal ◽  
Copper Hydroxide ◽  
X Ray ◽  
Modular Synthesis ◽  
Pendant Arm ◽  
Copper Center ◽  
Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands <sup>XpyMe</sup>TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>(<b>6a</b><b>–6e</b>) complexes were synthesized from the corresponding <sup>XpyMe</sup>TpCu–OAc (<b>5a–5e</b>) complexes. Single crystal X-ray structures of three new dinuclear [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric <sup>DMAPMe</sup>TpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈<sub>OH </sub>frequencies that tracks with the H-bond accepting ability of the pendant arm.

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

2019 ◽  
Author(s):  
Evan Gardner ◽  
Caitlyn Cobb ◽  
Jeffery A. Bertke ◽  
Timothy H. Warren
Keyword(s):  
Single Crystal ◽  
Copper Hydroxide ◽  
X Ray ◽  
Modular Synthesis ◽  
Pendant Arm ◽  
Copper Center ◽  
Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands <sup>XpyMe</sup>TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>(<b>6a</b><b>–6e</b>) complexes were synthesized from the corresponding <sup>XpyMe</sup>TpCu–OAc (<b>5a–5e</b>) complexes. Single crystal X-ray structures of three new dinuclear [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric <sup>DMAPMe</sup>TpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈<sub>OH </sub>frequencies that tracks with the H-bond accepting ability of the pendant arm.

Elemental sulfur in Eddy County, New Mexico

Circular ◽  
1970 ◽  
Author(s):  
Jim S. Hinds ◽  
Richard R. Cunningham
Keyword(s):  
New Mexico ◽  
Elemental Sulfur
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