Electrochemical synthesis of Isobenzofuran-1-imines using Oxidative Halocyclization of o‑Alkynylbenzamides

2021 ◽  
Author(s):  
Anandhan Ramasamy ◽  
Mandapati Bhargava Reddy ◽  
Raja Gopal P ◽  
Muthuraaman B
Keyword(s):  
Electrochemical Synthesis ◽  
Reaction Conditions

Electrochemical oxidative 5-exo-dig-oxo-halocyclization of o-alkynylbenzamides was achieved using readily available NaX (X = Cl, Br and I) salts under mild reaction conditions. The use of cheap and highly stable sodium...

Electrochemical synthesis of tetrazoles via metal- and oxidant-free [3 + 2] cycloaddition of azides with hydrazones

2018 ◽  
Vol 20 (23) ◽  
pp. 5271-5275 ◽  
Author(s):  
Zenghui Ye ◽  
Feng Wang ◽  
Yong Li ◽  
Fengzhi Zhang
Keyword(s):  
Functional Groups ◽  
Electrochemical Synthesis ◽  
Cycloaddition Reaction ◽  
Simple Metal ◽  
Reaction Conditions ◽  
Green Protocol

An unprecedented electrochemical [3 + 2] cycloaddition reaction for the synthesis of valuable tetrazoles was developed. Readily available azides and hydrazones were used as the starting materials under simple metal- and oxidant-free reaction conditions. Various functional groups are compatible with this green protocol.

Electrochemical Synthesis of Sulfinic Esters via Aerobic Oxidative Esterification of Thiophenols with Alcohols

Synthesis ◽  
2020 ◽  
Vol 52 (18) ◽  
pp. 2705-2712 ◽  
Author(s):  
Jingya Yang ◽  
Xi-Cun Wang ◽  
Hongyan Zhou ◽  
Jiaokui Duan ◽  
Dongtai Xie ◽  
...  
Keyword(s):  
Electrochemical Synthesis ◽  
Oxidative Coupling ◽  
Room Temperature ◽  
Reaction Conditions ◽  
Oxidative Esterification ◽  
Scale Preparation ◽  
Redox Reagent ◽  
Sulfinic Esters

A method for the electrochemical synthesis of sulfinic esters by aerobic oxidative coupling of thiophenols and alcohols has been developed. Using electrons as the redox reagent and O2 in air as the oxygen source, the reactions proceeded smoothly at room temperature, even for a gram-scale preparation. No use of catalyst, clean redox reagent, green and abundant oxygen source, and mild reaction conditions make this strategy eco-friendly.

Metal- and oxidant-free electrochemical synthesis of sulfinic esters from thiols and alcohols

2019 ◽  
Vol 21 (20) ◽  
pp. 5528-5531 ◽  
Author(s):  
Chongren Ai ◽  
Haiwei Shen ◽  
Dingguo Song ◽  
Yujin Li ◽  
Xiao Yi ◽  
...  
Keyword(s):  
Electrochemical Synthesis ◽  
Reaction Conditions ◽  
Sulfinic Esters

An eco-friendly electrochemical synthesis of sulfinic esters from thiols and alcohols under mild reaction conditions has been developed.

Nucleosides. III. Investigation of the Electrochemical Synthesis of N4, O5'-Diacetyl-2',3'-dideoxy-2',3'-didehydrocytidine

1994 ◽  
Vol 47 (10) ◽  
pp. 1843 ◽  
Author(s):  
O Johansen ◽  
SM Marcuccio ◽  
AWH Mau
Keyword(s):  
Current Density ◽  
Electrochemical Synthesis ◽  
Electrode Surface ◽  
Aprotic Solvents ◽  
Reaction Conditions ◽  
Protic Solvents ◽  
Half Wave ◽  
First Time ◽  
By Products ◽  
Base Moiety

The influence of the reaction conditions on the yield of N4,O5′-diacetyl-2′,3′-dideoxy-2′,3′-didehydrocytidine (3), by electrochemical synthesis from N4,O2′,O5′-triacetyl-3′-bromo-3′-deoxycytidine (2), has been studied in order to evaluate the potential of this reaction for synthesis on a larger scale. We have characterized the half-wave potentials of the precursor (2) and the product (3) by polarography under various conditions, and found that reduction in the base moiety can easily take place giving by-products. Furthermore, this reduction consumes protons leading to rapid solvolysis in protic solvents. We have demonstrated for the first time that (3) can be formed near quantitatively in both protic and aprotic solvents. The success of the synthesis of (3) as well as of other 2′,3′-dideoxy 2′,3′-didehydro nucleosides also depends to a large extent on how uniform the current density across the working electrode surface can be maintained during electrolysis.

Undecagold labeling of tRNA

1991 ◽  
Vol 49 ◽  
pp. 44-45
Author(s):  
James F. Hainfeld ◽  
Kyra M. Alford ◽  
Mathias Sprinzl ◽  
Valsan Mandiyan ◽  
Santa J. Tumminia ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Electron Micrograph ◽  
Anticodon Loop ◽  
Electron Micrograph ◽  
Reaction Conditions ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

The undecagold (Au11) cluster was used to covalently label tRNA molecules at two specific ribonucleotides, one at position 75, and one at position 32 near the anticodon loop. Two different Au11 derivatives were used, one with a monomaleimide and one with a monoiodacetamide to effect efficient reactions.The first tRNA labeled was yeast tRNAphe which had a 2-thiocytidine (s2C) enzymatically introduced at position 75. This was found to react with the iodoacetamide-Aun derivative (Fig. 1) but not the maleimide-Aun (Fig. 2). Reaction conditions were 37° for 16 hours. Addition of dimethylformamide (DMF) up to 70% made no improvement in the labeling yield. A high resolution scanning transmission electron micrograph (STEM) taken using the darkfield elastically scattered electrons is shown in Fig. 3.

Dimensionally-Controlled Hydrothermal Tm3+-doped Oxidic Nanocrystals and Their Photoluminescence Properties

2010 ◽  
Vol 1247 ◽  
Author(s):  
Rocío Calderón-Villajos ◽  
Carlos Zaldo ◽  
Concepción Cascales
Keyword(s):  
Single Crystals ◽  
Fluorescence Lifetimes ◽  
Photoluminescence Properties ◽  
Reaction Conditions ◽  
Hydrothermal Processes ◽  
Bulk Single Crystals ◽  
Template Free ◽  
Reaction Media

AbstractControlled reaction conditions in simple, template-free hydrothermal processes yield Tm-Lu2O3 and Tm-GdVO4 nanocrystals with well-defined specific morphologies and sizes. In both oxide families, nanocrystals prepared at pH 7 reaction media exhibit photoluminescence in ∼1.95 μm similar to bulk single crystals. For the lowest Tm3+ concentration (0.2 % mol) in GdVO4 measured 3H4 and 3F4 fluorescence lifetimes τ are very near to τrad.

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

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