2016年11月29日火曜日

Ethinamide 2016

Kinetics and Mechanism of Bioactivation via S-Oxygenation of Anti-Tubercular Agent Ethionamide by Peracetic Acid

^† Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States

^‡ School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa

J. Phys. Chem. A, 2016, 120 (41), pp 8056–8064

DOI: 10.1021/acs.jpca.6b07375

Publication Date (Web): September 29, 2016

*E-mail address: rsimoyi@pdx.edu; phone number: 503-725-3895.

Abstract

The kinetics and mechanism of the oxidation of the important antitubercular agent, ethionamide, ETA (2-ethylthioisonicotinamide), by peracetic acid (PAA) have been studied. It is effectively a biphasic reaction with an initial rapid first phase of the reaction which is over in about 5 s and a second slower phase of the reaction which can run up to an hour. The first phase involves the addition of a single oxygen atom to ethionamide to form the S-oxide. The second phase involves further oxidation of the S-oxide to desulfurization of ETA to give 2-ethylisonicotinamide. In contrast to the stability of most organosulfur compounds, the S-oxide of ETA is relatively stable and can be isolated. In conditions of excess ETA, the stoichiometry of the reaction was strictly 1:1: CH₃CO₃H + Et(C₅H₄)C(═S)NH₂ → CH₃CO₂H + Et(C₅H₄)C(═NH)SOH. In this oxidation, it was apparent that only the sulfur center was the reactive site. Though ETA was ultimately desulfurized, only the S-oxide was stable. Electrospray ionization (ESI) spectral analysis did not detect any substantial formation of the sulfinic and sulfonic acids. This suggests that cleavage of the carbon–sulfur bond occurs at the sulfenic acid stage, resulting in the formation of an unstable sulfur species that can react further to form more stable sulfur species. In this oxidation, no sulfate formation was observed. ESI spectral analysis data showed a final sulfur species in the form of a dimeric sulfur monoxide species, H₃S₂O₂. We derived a bimolecular rate constant for the formation of the S-oxide of (3.08 ± 0.72) × 10² M^–1 s^–1. Oxidation of the S-oxide further to give 2-ethylisonicotinamide gave zero order kinetics.

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Ant-TB Compounds 2016

JUST TAKE A LOOK @

http://pubs.acs.org/action/doSearch?AllField=antituberculosis

2016年11月28日月曜日

Cobalt catalysed Carbonylation 2016

Please See the Following Pages;

http://pubs.acs.org/action/doSearch?AllField=Cobalt+Catalyzed+Carbonylation

Co Catalysed Carbonylation 2016

Cobalt-Catalyzed Carbonylation of C(sp²)–H Bonds with Azodicarboxylate as the Carbonyl Source

Jiabin Ni^†^‡, Jie Li^†^§, Zhoulong Fan^†^‡, and Ao Zhang^*^†^‡^§

^† CAS Key Laboratory of Receptor Research, and Synthetic Organic & Medicinal Chemistry Laboratory (SOMCL), Shanghai Institute of Materia Medica (SIMM), Chinese Academy of Sciences, Shanghai 201203, China

^‡ University of Chinese Academy of Sciences, Beijing 100049, China

^§ ShanghaiTech University, Shanghai 20120, China

Org. Lett., 2016, 18 (22), pp 5960–5963

DOI: 10.1021/acs.orglett.6b03111

Publication Date (Web): November 8, 2016

*E-mail: aozhang@simm.ac.cn.

Abstract

A novel and efficient approach for the C(sp²)–H bond carbonylation of benzamides has been developed using stable and inexpensive Co(OAc)₂·4H₂O as the catalyst and the commercially available and easily handling azodicarboxylates as the nontoxic carbonyl source.

A broad range of substrates bearing diverse functional groups were tolerated.

This is the first example where cobalt-catalyzed C(sp2)–H bond carbonylation occurs with azodicarboxylate as the carbonyl source.

Supporting Information

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.orglett.6b03111.

Experimental procedures, spectral and analytical data, copies of ¹H and ¹³C NMR spectra for new compounds (PDF)

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2016年11月24日木曜日

MODERN ORGANIC SYNTHESIS @ TCI Library　

TCI　寄稿論文　TCI

PDF is Now Availabale @

http://www.tcichemicals.com/ja/jp/support-download/article/

RSC Advances 2016: Nitration of Quinolines

Please See the colour Change in These Reactions;

Paper

Copper-catalyzed rapid C–H nitration of

8-aminoquinolines by using sodium nitrite

as the nitro source under mild conditions

Xiaolei Zhu,^a Li Qiao,^a Pingping Ye,^a Beibei Ying,^a Jun Xu,^a Chao Shen^b and Pengfei Zhang*^a

DOI: 10.1039/C6RA19583K
Received 03 Aug 2016, Accepted 16 Sep 2016
First published online 16 Sep 2016

A mild, rapid and efficient method for copper-catalyzed nitration of quinolines at the C5 or C7 position was reported firstly by using sodium nitrite as the nitro source. A series of nitrated quinoline derivatives were achieved in moderate to good yields via remote C–H activation. The method overcomes some shortcomings reported in previous nitration strategies, such as employing expensive metal catalysts or using toxic and unstable nitrating agents. Furthermore, some of the products can be obtained through filtration which displays the operational simplicity of this methodology. Importantly, this protocol may provide a practical synthetic tool for the introduction of nitro groups into drug molecules.

Graphical abstract: Copper-catalyzed rapid C–H nitration of 8-aminoquinolines by using sodium nitrite as the nitro source under mild conditions

RSC Advances 2016: Directed Metalation

For the Progress of Directed Functionalizatio of Heterocycles;

http://pubs.rsc.org/en/Content/ArticleLanding/2016/RA/C6RA19583K#!divRelatedContent

2016年11月21日月曜日

Halogenation via C-H Activation

The simplest and Versatile C-H Activation is

Obvious C-H Halogenation.

http://pubs.acs.org/action/doSearch?AllField=C%E2%88%92H+Activation+Halogenation

2016年11月20日日曜日

P$% DEHALOGENATIONS

DEHALOGENATION PROCESS By P450 Enzymes;

We Have To Learn More About Living Organic Reactions

Inside the Cells;

http://pubs.acs.org/action/doSearch?AllField=P450+dehalogenation&startPage=&sortBy=Earliest

Dehalogenation & Debromination 2016

Dehalogenation Updates:

http://pubs.acs.org/action/doSearch?AllField=debromination+dehalogenation&startPage=&sortBy=Earliest

2016年11月18日金曜日

Catalysed Iodination Selected 2013

Iodine(I) Reagents in Hydrochloric Acid-Catalyzed Oxidative Iodination of Aromatic Compounds by Hydrogen Peroxide and Iodine

Authors

1. Department of Physical and Organic Chemistry, Laboratory for Organic and Bioorganic Chemistry, “Jožef Stefan” Institute, Jamova 39, 1000 Ljubljana, Slovenia, Fax: (+386)-1251-9385; phone: (+386)-1477-3631
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Corresponding author
- E-mail address: jernej.iskra@ijs.si
1. Department of Physical and Organic Chemistry, Laboratory for Organic and Bioorganic Chemistry, “Jožef Stefan” Institute, Jamova 39, 1000 Ljubljana, Slovenia, Fax: (+386)-1251-9385; phone: (+386)-1477-3631
2. The Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins (CIPKeBiP), Jamova 39, 1000 Ljubljana, Slovenia
- Department of Physical and Organic Chemistry, Laboratory for Organic and Bioorganic Chemistry, “Jožef Stefan” Institute, Jamova 39, 1000 Ljubljana, Slovenia, Fax: (+386)-1251-9385; phone: (+386)-1477-3631

First published: 30 April 2013Full publication history
DOI: 10.1002/adsc.201300127View/save citation
Cited by: 8 articles

Abstract

Hydrochloric acid activates the oxidative iodination of aromatic compounds with the iodine- hydrogen peroxide system through the formation of an iodine(I) compound as the iodinating reagent. Activation with hydrochloric acid is more powerful than that with sulfuric acid. The formation of dichloroiodic(I) acid (HICl₂) with various forms of hydrogen peroxide was followed using UV spectroscopy. The HICl₂ was used as the iodinating reagent. In the preparative oxidative iodinaton of various aromatic compounds, hydrochloric acid was used in a catalytic amount and the iodine(I) reagent was formed in situ with 0.5 equiv. hydrogen peroxide and 0.5 equiv. molecular iodine. Two types of reactivity were observed in oxidative iodination with iodine(I) species catalyzed by hydrochloric acid: in the iodination of anisole 1a better yields of iodination were observed with a smaller amount of hydrochloric acid, while on the contrary 4-tert-butyltoluene 1b gave better yields of iodination upon increasing the amount of hydrochloric acid. Reactivity was further manipulated by the choice of the solvent (MeCN, trifluoroethanol, hexafluoro-2-propanol).

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Article Information

DOI

10.1002/adsc.201300127

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Keywords

halogenation;
hydrogen peroxide;
iodination;
oxidation;
oxidative iodination

Publication History

Issue online: 10 May 2013
Version of record online: 30 April 2013
Manuscript Revised: 12 April 2013
Manuscript Received: 7 February 2013

Funded by

Slovenian Research Agency. Grant Number: PR-04115

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Citing Literature

Catalytic Bromination Update 2016

For the Variation of Catalytic Bromination Avenue;

Please See the Following Alignments:

http://pubs.acs.org/action/doSearch?AllField=Catalytic+Bromination&sortBy=Earliest&pageSize=20&startPage=1

Catalytic Carbonylation　Update　２０１６

Please　Check　Every　Catalytic Procedures;

The Obvious Final Goal is Instalation of CO2,

Instead of CO.

http://pubs.acs.org/action/doSearch?AllField=Catalyzed+Carbonylation&type=within&publication=

2016年11月17日木曜日

Cu Mediated Directed Nitration 2011

Copper-Mediated Chelation-Assisted Ortho Nitration of (Hetero)arenes

Lin Zhang^†, Zhenhua Liu^†, Huiqin Li^†, Guichun Fang^†, Badru-Deen Barry^†, Tuemay Abadi Belay^†, Xihe Bi^†^‡, and Qun Liu^†

Department of Chemistry, Northeast Normal University, Changchun 130024, China, and State Key Laboratory of Fine Chemicals, School of Chemical Engineering, University of Technology, Dalian 116012, China

Org. Lett., 2011, 13 (24), pp 6536–6539

DOI: 10.1021/ol2028288

Publication Date (Web): November 11, 2011

bixh507@nenu.edu.cn; liuqun@nenu.edu.cn,

Northeast Normal University.

University of Technology.

Abstract

A novel copper-mediated chelation-assisted ortho C–H nitration of (hetero)arenes has been developed for the first time, which used dioxygen as terminal oxidant and 1,2,3-TCP as solvent, leading to the synthesis of nitroaromatics with excellent regioselectivity and in good yields. Mechanistic investigations indicate a mechanism involving a four-centered transition state, with simultaneous cleavage of an ortho C–H bond and a N–O bond of the nitrate anion on the 2-arylpyridine-coordinated copper(II) complex.

Supporting Information

Experimental procedures, spectra, and analytical data for 2a/2b. This material is available free of charge via the Internet at http://pubs.acs.org.

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Proofs

Copper-Mediated Chelation-Assisted Ortho Nitration of (Hetero)arenes

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