scholarly journals Halogen–Sodium Exchange Revisited

2020 ◽  
Author(s):  
Sobi Asako ◽  
Ikko Takahashi ◽  
Hirotaka Nakajima ◽  
Laurean Ilies ◽  
Kazuhiko Takai
Keyword(s):  
Organic Synthesis ◽  
Present Method ◽  
Sustainable Chemistry ◽  
Exchange Method ◽  
New Horizons ◽  
Hydrogen Elimination ◽  
Organolithium Reagents ◽  
Organosodium Compounds ◽  
Sodium Exchange

<p>Sodium is the most abundant alkali metal on Earth. Despite being an attractive choice for sustainable synthesis, organosodium compounds are rarely used in organic synthesis and have been overshadowed to date by organolithium compounds. This situation is largely due to the lack of convenient and efficient methods for the preparation of organosodium compounds. We report herein a halogen–sodium exchange method to prepare a large variety of (hetero)aryl- and alkenylsodium compounds, many of them previously inaccessible by other methods. The key discovery is the use of a bulky alkylsodium lacking a <i>β</i>-hydrogen, readily prepared in situ from neopentyl chloride and an easy-to-handle sodium dispersion, which retards undesired reactions such as Wurtz–Fittig coupling and <i>β</i>-hydrogen elimination, and enables efficient halogen-sodium exchange. We believe that the efficiency, generality, and convenience of the present method will open new horizons for the use of organosodium in organic synthesis, ultimately contributing to the development of sustainable chemistry by replacing the currently dominant organolithium reagents.<b></b></p>

scholarly journals Halogen–Sodium Exchange Revisited

2020 ◽  
Author(s):  
Sobi Asako ◽  
Ikko Takahashi ◽  
Hirotaka Nakajima ◽  
Laurean Ilies ◽  
Kazuhiko Takai
Keyword(s):  
Organic Synthesis ◽  
Present Method ◽  
Sustainable Chemistry ◽  
Exchange Method ◽  
New Horizons ◽  
Hydrogen Elimination ◽  
Organolithium Reagents ◽  
Organosodium Compounds ◽  
Sodium Exchange

<p>Sodium is the most abundant alkali metal on Earth. Despite being an attractive choice for sustainable synthesis, organosodium compounds are rarely used in organic synthesis and have been overshadowed to date by organolithium compounds. This situation is largely due to the lack of convenient and efficient methods for the preparation of organosodium compounds. We report herein a halogen–sodium exchange method to prepare a large variety of (hetero)aryl- and alkenylsodium compounds, many of them previously inaccessible by other methods. The key discovery is the use of a bulky alkylsodium lacking a <i>β</i>-hydrogen, readily prepared in situ from neopentyl chloride and an easy-to-handle sodium dispersion, which retards undesired reactions such as Wurtz–Fittig coupling and <i>β</i>-hydrogen elimination, and enables efficient halogen-sodium exchange. We believe that the efficiency, generality, and convenience of the present method will open new horizons for the use of organosodium in organic synthesis, ultimately contributing to the development of sustainable chemistry by replacing the currently dominant organolithium reagents.<b></b></p>

scholarly journals Halogen–sodium exchange enables efficient access to organosodium compounds

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sobi Asako ◽  
Ikko Takahashi ◽  
Hirotaka Nakajima ◽  
Laurean Ilies ◽  
Kazuhiko Takai
Keyword(s):  
Organic Synthesis ◽  
Present Method ◽  
Exchange Method ◽  
Preparation Methods ◽  
Hydrogen Elimination ◽  
Efficient Access ◽  
Organolithium Reagents ◽  
Organosodium Compounds ◽  
Sodium Exchange

AbstractWith sodium being the most abundant alkali metal on Earth, organosodium compounds are an attractive choice for sustainable chemical synthesis. However, organosodium compounds are rarely used—and are overshadowed by organolithium compounds—because of a lack of convenient and efficient preparation methods. Here we report a halogen–sodium exchange method to prepare a large variety of (hetero)aryl- and alkenylsodium compounds including tri- and tetrasodioarenes, many of them previously inaccessible by other methods. The key discovery is the use of a primary and bulky alkylsodium lacking β-hydrogens, which retards undesired reactions, such as Wurtz–Fittig coupling and β-hydrogen elimination, and enables efficient halogen–sodium exchange. The alkylsodium is readily prepared in situ from neopentyl chloride and an easy-to-handle sodium dispersion. We believe that the efficiency, generality, and convenience of the present method will contribute to the widespread use of organosodium in organic synthesis, ultimately contributing to the development of sustainable organic synthesis by rivalling the currently dominant organolithium reagents.

scholarly journals Ni-Electrocatalytic C(sp3)–C(sp3) Doubly Decarboxylative Coupling

2021 ◽  
Author(s):  
benxiang zhang ◽  
yang gao ◽  
yuta hioki ◽  
martins oderinde ◽  
jennifer qiao ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Present Method ◽  
Bond Formation ◽  
Amide Bond ◽  
Bond Forming ◽  
Amide Bond Formation ◽  
Redox Active ◽  
Decarboxylative Coupling ◽  
The 19Th Century

This work presents a modern spin on one of the oldest known Csp3–Csp3 bond forming reactions in synthetic chemistry: the Kolbe electrolysis. This reaction holds incredible promise for synthesis, yet its use has been near non-existent in mainstream organic synthesis. In contrast to the strongly oxidative electrolytic protocol employed traditionally since the 19th century, the present method utilizes in situ generated redox-active esters (RAEs) which are combined with a mildly reductive Ni-electrocatalytic cycle. It can be used to heterocouple 1o, 2o, and even certain 3o RAEs with a protocol reminiscent of amide bond formation in terms of simplicity. Due to its mild nature the reaction tolerates a range of functional groups, is scalable, and was strategically enlisted for the synthesis of 25 known compounds to reduce overall step-counts by 74%.

A Mild and Simple Method for Making MIDA Boronates

2020 ◽  
Author(s):  
Aidan Kelly ◽  
Peng-Jui (Ruby) Chen ◽  
Jenna Klubnick ◽  
Daniel J. Blair ◽  
Martin D. Burke
Keyword(s):  
Organic Synthesis ◽  
Boronic Acids ◽  
Simple Method ◽  
Direct Preparation ◽  
Synthesis Procedure ◽  
Harsh Conditions

<div> <div> <div> <p>Existing methods for making MIDA boronates require harsh conditions and complex procedures to achieve dehydration. Here we disclose that a pre-dried form of MIDA, MIDA anhydride, acts as both a source of the MIDA ligand and an in situ desiccant to enable a mild and simple MIDA boronate synthesis procedure. This method expands the range of sensitive boronic acids that can be converted into their MIDA boronate counterparts. Further utilizing unique properties of MIDA boronates, we have developed a MIDA Boronate Maker Kit which enables the direct preparation and purification of MIDA boronates from boronic acids using only heating and centrifuge equipment that is widely available in labs that do not specialize in organic synthesis. </p> </div> </div> </div>

Recent advances in Minisci-type reactions and applications in organic synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Wengui Wang ◽  
Shoufeng Wang
Keyword(s):  
Free Radical ◽  
Hydrogen Atom ◽  
Organic Synthesis ◽  
Radical Reactivity ◽  
Atom Loss ◽  
Radical Generation ◽  
In Situ Generation ◽  
Thermal Cleavage ◽  
Synthetic Chemist

Abstract:: Minisci-type reactions have become widely known as reactions that involve the addition of carbon-centered radicals to basic heteroarenes followed by formal hydrogen atom loss. While the originally developed protocols for radical generation remain in active use today, in recent years by a new array of radical generation strategies allow use of a wider variety of radical precursors that often operate under milder and more benign conditions. New transformations based on free radical reactivity are now available to a synthetic chemist looking to utilize a Minisci-type reaction. Radical-generation methods based on photoredox catalysis and electrochemistry, which utilize thermal cleavage or the in situ generation of reactive radical precursors, have become popular approaches. Our review will cover the remarkably literature that has appeared on this topic in recent 5 years, from 2015-01 to 2020-01, in an attempt to provide guidance to the synthetic chemist, on both the challenges that have been overcome and applications in organic synthesis.

Surface modification of sewage sludge derived carbonaceous catalyst for m-cresol catalytic wet peroxide oxidation and degradation mechanism

RSC Advances ◽  
2015 ◽  
Vol 5 (52) ◽  
pp. 41867-41876 ◽  
Author(s):  
Yang Yu ◽  
Huangzhao Wei ◽  
Li Yu ◽  
Tong Zhang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Sewage Sludge ◽  
Organic Synthesis ◽  
Degradation Mechanism ◽  
Peroxide Oxidation ◽  
Wet Peroxide Oxidation ◽  
Carbonaceous Catalyst ◽  
Catalytic Wet Peroxide Oxidation

Organic synthesis is used to investigate the degradation of m-cresol and the intermediates are identified by in situ NMR.

Preparation of novel AgBr/Bi 3 O 4 Br hybrid with high photocatalytic activity via in situ ion exchange method

2017 ◽  
Vol 193 ◽  
pp. 73-76 ◽  
Author(s):  
Jingxiong Yu ◽  
Min Cui ◽  
Xingzheng Liu ◽  
Qianqian Chen ◽  
Ying Wu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Ion Exchange ◽  
High Photocatalytic Activity ◽  
Exchange Method ◽  
Ion Exchange Method

The aryl iodine-catalyzed organic transformation via hypervalent iodine species generated in situ

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xuemin Li ◽  
Guangchen Li ◽  
Yifu Cheng ◽  
Yunfei Du
Keyword(s):  
Organic Synthesis ◽  
Oxidative Coupling ◽  
Hypervalent Iodine ◽  
Organic Transformations ◽  
Aryl Iodide ◽  
Oxidative Reaction ◽  
Iodine Species ◽  
Iodine Chemistry

Abstract The application of hypervalent iodine species generated in situ in organic transformations has emerged as a useful and powerful tool in organic synthesis, allowing for the construction of a series of bond formats via oxidative coupling. Among these transformations, the catalytic aryl iodide can be oxidized to hypervalent iodine species, which then undergoes oxidative reaction with the substrates and the aryl iodine regenerated again once the first cyclic cycle of the reaction is completed. This review aims to systematically summarize and discuss the main progress in the application of in situ-generated hypervalent iodine species, providing references and highlights for synthetic chemists who might be interested in this field of hypervalent iodine chemistry.

Flow Chemistry: The Direct Production of Drug Metabolites

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Synthesis ◽  
Flow Chemistry ◽  
Florida State University ◽  
State University ◽  
Max Planck ◽  
Direct Production ◽  
Reactor Technology ◽  
University Of Cambridge ◽  
The University

Several overviews of flow chemistry appeared recently. Katherine S. Elvira and Andrew J. deMello of ETH Zürich wrote (Nature Chem. 2013, 5, 905) on micro­fluidic reactor technology. D. Tyler McQuade of Florida State University and the Max Planck Institute Mühlenberg reviewed (J. Org. Chem. 2013, 78, 6384) applications and equipment. Jun-ichi Yoshida of Kyoto University focused (Chem. Commun. 2013, 49, 9896) on transformations that cannot be effected under batch condi­tions. Detlev Belder of the Universität Leipzig reported (Chem. Commun. 2013, 49, 11644) flow reactions coupled to subsequent micropreparative separations. Leroy Cronin of the University of Glasgow described (Chem. Sci. 2013, 4, 3099) combin­ing 3D printing of an apparatus and liquid handling for convenient chemical synthe­sis and purification. Many of the reactions of organic synthesis have now been adapted to flow con­ditions. We will highlight those transformations that incorporate particularly useful features. One of those is convenient handling of gaseous reagents. C. Oliver Kappe of the Karl-Franzens-University Graz generated (Angew. Chem. Int. Ed. 2013, 52, 10241) diimide in situ to reduce 1 to 2. David J. Cole-Hamilton immobilized (Angew. Chem. Int. Ed. 2013, 52, 9805) Ru DuPHOS on a heteropoly acid support, allowing the flow hydrogenation of neat 3 to 4 in high ee. Steven V. Ley of the University of Cambridge added (Org. Process Res. Dev. 2013, 17, 1183) ammonia to 5 to give the thiourea 6. Alain Favre-Réguillon of the Conservatoire National des Arts et Métiers used (Org. Lett. 2013, 15, 5978) oxygen to directly oxidize the aldehyde 7 to the car­boxylic acid 8. Professor Kappe showed (J. Org. Chem. 2013, 78, 10567) that supercritical ace­tonitrile directly converted an acid 9 to the nitrile 10. Hisao Yoshida of Nagoya University added (Chem. Commun. 2013, 49, 3793) acetonitrile to nitrobenzene 11 to give the para isomer 12 with high regioselectively. Kristin E. Price of Pfizer Groton coupled (Org. Lett. 2013, 15, 4342) 13 to 14 to give 15 with very low loading of the Pd catalyst. Andrew Livingston of Imperial College demonstrated (Org. Process Res. Dev. 2013, 17, 967) the utility of nanofiltration under flow conditions to minimize Pd levels in a Heck product.

scholarly journals DESIGN, DEVELOPMENT, AND EVALUATION OF AN ION-ACTIVATED OPHTHALMIC IN SITU GEL OF MOXIFLOXACIN HYDROCHLORIDE

2019 ◽  
pp. 94-103
Author(s):  
GIRISH KONDALKAR ◽  
ASISH DEV
Keyword(s):  
Drug Release ◽  
Sodium Alginate ◽  
Statistical Models ◽  
Bacterial Infections ◽  
Gelling Agent ◽  
Design Development ◽  
Sustained Drug Release ◽  
Exchange Method ◽  
In Situ Gelling

Objective: The objective of this study was to develop an in situ ophthalmic gel of an anti-infective drug, moxifloxacin (MOX) hydrochloride (HCL), for sustained ocular delivery for the treatment of bacterial infections of the eye. Method: In the present work the in situ gelling systems were prepared by ion exchange method with the help of various concentrations of gelling agent gelrite (0.08 g, 0.1 g and 0.12 g) and sodium alginate (0.6 g, 0.8 g and 1 g) as viscosity enhancer were added in the formulation; 9 formulations were prepared according to 32 factorial designs and evaluated. The responses were analyzed for the analysis of variance using Design-Expert version 10 software. Statistical models were generated for each response parameter. Results: Optimized formulation batch F7 (0.12% gelrite and 0.6% sodium alginate) was liquid before addition of simulated tear fluid (STF) and underwent rapid gelation on addition of STF and had given 84.05% cumulative drug release; the formulation was found to be clear, having good in situ gelling capacity, good antibacterial efficacy, having drug content 99.75%; optimized formulation was sterile and showed sustained drug release over 8 h period as compared to marketed eye drop. Conclusions: From the above results, we can concluded that 32 full factorial design and statistical models can be successfully used to optimize the formulations, and it was concluded that the trial batch F7 (0.12% gelrite and 0.6% sodium alginate) is the best formula (percentage cumulative drug release over 84.05%) and it is possible to formulate in situ ophthalmic gels of MOX HCL using gelrite in combination with sodium alginate for the treatment of various bacterial infections of the eyes.

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