Over the last 20 years organic carbamates have found numerous applications in pesticides, fungicides, herbicides, dyes, pharmaceuticals, cosmetics, and as protecting groups and intermediates for polyurethane synthesis. Recently, in order to avoid phosgene-based synthesis of carbamates, many environmentally benign and alternative pathways have been investigated. However, few examples of carbamoylation of aniline in continuous-flow apparatus have been reported. In this work, we report a high-yielding, dimethyl carbonate (DMC)-mediated carbamoylation of aniline in a fixed-bed continuously fed reactor employing basic zinc carbonate as catalyst. Several variables of the system have been investigated (i.e. molar ratio of reagents , flow rate, and reaction temperature) to optimize the operating conditions of the system.

Highly Selective Phosgene-Free Carbamoylation of Aniline by Dimethyl Carbonate under Continuous-Flow Conditions

Sandra Grego, Fabio Aricò, and Pietro Tundo*

Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice, Dorsoduro 2137, 30123 Venezia, Italia

Org. Process Res. Dev., 2013, 17 (4), pp 679–683

DOI: 10.1021/op4000048, http://pubs.acs.org/doi/abs/10.1021/op4000048

*Tel.: (+39) 041 234 8642. Fax: (+39) 041 234 8620. E-mail: tundop@unive.it.

 

PIETRO TUNDO

Profile:

PIETRO R. TUNDO is Professor of Organic Chemistry at Ca’ Foscari University of Venice (Italy). 
He was guest researcher and teacher at College Station (Texas,1979-1981), Potsdam (New York, 1989-90) and Syracuse (New York, 1991-92), Chapel Hill, (North Carolina, 1995). 
He is Member of the Bureau of IUPAC.

P: Tundo is author of about 300 scientific publications, 40 patents and many books. 
His scientific interests are in the field of organic synthesis in selective methylations with low environmental impact, continuous flow chemistry, chemical detoxification of contaminants, hydrodehalogenation under multiphase conditions, phase-transfer catalysis (gas-liquid phase-transfer catalysis, GL-PTC), synthesis of crown-ethers and functionalized cryptands, supramolecular chemistry, heteropolyacids, and finally safe alternatives to harmful chemicals. 
He is the sole author of the book “Continuous flow methods in organic synthesis” E. Horwood Pub., Chichester, UK, 1991 (378 pp.), and editor of about 15 books.

P. Tundo was President of Organic and Biomolecular Chemistry Division of IUPAC (biennium 2007-2009) and holder of the Unesco Chair on Green Chemistry (UNTWIN N.o 731). He founded and was Chairman (2004-2016) of the Working Party on “Green and Sustainable Chemistry” of Euchems (European Association for Chemical and Molecular Sciences).
Founder of the IUPAC International Conferences Series on Green Chemistry, he was awarded by American Chemical Society on 1983 (Kendall Award, with Janos Fendler), and by Federchimica (Italian association of chemical industries) on 1997 (An Intelligent Future).
P. Tundo coordinated many institutional and industrial research projects (EU, NATO, Dow, ICI, Roquette) and was Director of the 10 editions of the annual Summer School on Green Chemistry (Venezia, Italy) sponsored by the EU, UNESCO and NATO.
He was guest researcher and teacher at College Station (Texas,1979-1981), Potsdam (New York, 1989-90) and Syracuse (New York, 1991-92), Chapel Hill, (North Carolina, 1995).
He is holder of the Unesco Chair on Green Chemistry (UNTWIN N.o 731) and author of about 260 scientific publications and 30 patents.
Scientific interests are in the field of organic synthesis in selective methylations with low environmental impact, continuous flow chemistry, chemical detoxification of contaminants, hydrodehalogenation under multiphase conditions, phase-transfer catalysis (gas-liquid phase-transfer catalysis, GL-PTC), synthesis of crown-ethers and functionalized cryptands, supramolecular chemistry and finally, heteropolyacids.
He is the sole author of the book "Continuous flow methods in organic synthesis" E. Horwood Pub., Chichester, UK, 1991 (378 pp.), and editor of about 15 books.
P. Tundo was President of Organic and Biomolecular Chemistry Division of IUPAC (biennium 2007-2009) and presently is Chairman of Working Party of "Green and Sustainable Chemistry" of Euchems (European Association for Chemical and Molecular Sciences).
Founder of the IUPAC International Conferences Series on Green Chemistry, he was awarded by American Chemical Society on 1983 (Kendall Award, with Janos Fendler), and by Federchimica (Italian association of chemical industries) on 1997 (An Intelligent Future).
P. Tundo co-ordinated many institutional and industrial research projects (EU, NATO, Dow, ICI, Roquette) and was Director of the 10 editions of the annual Summer School on Green Chemistry (Venezia), the latter sponsored by the EU, UNESCO and NATO.

Contact:

Professor of Organic Chemistry
Ca’ Foscari University of Venice
IUPAC Bureau Member
Tel. +39 041 2348642
Mob. +39 349 3486191
E-mail: tundop@unive.it

Phone	041 234 8642 / Lab .: 041 234 8669
E-mail	tundop@unive.it  green.chemistry@unive.it - 6th IUPAC Conference on Green Chemistry unescochair@unive.it - TUNDO Pietro
Fax	041 234 8620
Web	www.unive.it/persone/tundop

Pietro Tundo

////////Carbamoylation of Aniline, Dimethyl Carbonate, Continuous-Flow Conditions, flow synthesis

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

Rhodium-catalyzed regiospecific C-H ortho-phenylation of benzoic acids with Cu/air as an oxidant

Rhodium-catalyzed regiospecific C-H ortho-phenylation of benzoic acids with Cu/air as an oxidant

Org. Chem. Front., 2017, Advance Article
DOI: 10.1039/C6QO00663A, Research Article

Shiguang Li, Guo-Jun Deng, Feifei Yin, Chao-Jun Li, Hang Gong
An efficient and practical synthetic approach for the regiospecific C-H ortho-phenylation of aromatic carboxylic acids in the absence of silver.

Rhodium-catalyzed regiospecific C–H ortho-phenylation of benzoic acids with Cu/air as an oxidant

Shiguang Li,^a   Guo-Jun Deng,^a   Feifei Yin,^a  Chao-Jun Li*^b and   Hang Gong*^a  *

Corresponding authors

^a

The Key Laboratory of Environmentally Friendly Chemistry and Application of the Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
 E-mail: hgong@xtu.edu.cn

^b

Department of Chemistry and FQRNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke St. W., Montreal, Canada
 E-mail: cj.li@mcgill.ca

Org. Chem. Front., 2017, Advance Article

DOI: 10.1039/C6QO00663A

http://pubs.rsc.org/en/Content/ArticleLanding/2017/QO/C6QO00663A#!divAbstract

The development of an efficient and practical synthetic approach for the regiospecific C–H ortho-phenylation of aromatic carboxylic acids without the use of silver or costly coupling partners is reported. The rhodium-catalyzed C–H phenylation proceeded in the presence of Cu/air as a terminal oxidant. In most cases, numerous inactivated benzoic acids could couple with low-cost NaBPh₄ to obtain good to excellent yields.

A solution of aromatic acid 1a (27.2 mg, 0.2 mmol), NaBPh4 (0.27 g, 0.8 mmol), KF (46 mg, 0.8 mmol), [Rh(nbd)Cl]2 (9.2 mg, 0.02 mmol) and CuBr2 (4.5 mg, 0.02 mmol) in chlorobenzene (1.2 mL) was stirred in a sealed tube under air at 150 oC for 24 h. The reaction mixture was then cooled to room temperature and acidified by dilute aqueous HCl to pH<3, and then the solvent was evaporated in vacuo. The residue was purified by preparative thin-layer chromatography (TLC) on silica gel with petroleum ether and ethyl acetate as eluent to give the pure product 2a.

2a White solid; Yield 86%; Mp 132-134 oC [lit1 mp 133-135oC]; IR (neat) νmax 3057, 2917, 2849, 2627, 1682, 1461, 1133, 1064, 1000, 759, 696 cm-1; 1H NMR (400 MHz, CDCl3): δ = 7.35-7.40 (m, 6H), 7.23 (m, 2H), 2.45 (s, 3H); 13C NMR (100 MHz, CDCl3) δ = 174.5, 140.7, 140.2, 135.5, 132.2, 129.7, 129.2, 128.4 (2C), 127.6, 127.5, 20.0; HRMS (ESI) m/z calcd for C14H13O2 213.0910, found [M+H] + 213.0912.

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Eco-Friendly, Catalyst and Solvent-Free, Synthesis of Acetanilides and N-Benzothiazole-2-yl-acetamides

N-(o-Tolyl)acetamide (3b) White solid, 51.5 mg, 71% yield; m.p. 108.4-109.0 °C (Lit.27 108-109 °C); IR (KBr) n / cm-1 3291, 1647, 1587, 1527, 1458, 1369, 1271, 1116, 1039, 933, 854, 756, 698, 651, 607; 1H NMR (500 MHz, CDCl3) d 2.19 (s, 3H, CH3), 2.30 (s, 3H, CH3), 7.10 (t, 1H, J 7.5 Hz, CH), 7.21 (t, 1H, J 8.0 Hz, CH), 7.71 (d, 1H, J 8.0 Hz, CH); 13C NMR (125 MHz, CDCl3) d 17.8, 24.2, 123.7, 125.4, 126.7, 129.7, 130.5, 135.6, 168.6.

Short ReportJ. Braz. Chem. Soc. 2016

Eco-Friendly, Catalyst and Solvent-Free, Synthesis of Acetanilides and N-Benzothiazole-2-yl-acetamides

Silvio Cunha; Lourenço L. B. de Santana

An expeditious and green synthesis of acetamides is described in good yield without external heating, and with simple purification. 

This paper is part of the PubliSBQ Special Issue in honor of the late Prof Angelo da Cunha Pinto.

http://dx.doi.org/10.21577/0103-5053.20160265

Published online: September 27, 2016.

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Synthesis of symmetrical pyridines by iron-catalyzed cyclization of ketoxime acetates and aldehydes

Synthesis of symmetrical pyridines by iron-catalyzed cyclization of ketoxime acetates and aldehydes

Green Chem., 2017, Advance Article
DOI: 10.1039/C6GC03137D, Paper

YuKun Yi, Mi-Na Zhao, Zhi-Hui Ren, Yao-Yu Wang, Zheng-Hui Guan
A facile iron-catalyzed cyclization of aldehydes with ketoxime acetates for the synthesis of multisubstituted symmetrical pyridines has been developed.

Synthesis of symmetrical pyridines by iron-catalyzed cyclization of ketoxime acetates and aldehydes

YuKun Yi,^a   Mi-Na Zhao,^a   Zhi-Hui Ren,^a  Yao-Yu Wang^a and   Zheng-Hui Guan*^a  

*

Corresponding authors

^a

Key Laboratory of Synthetic and Nature Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science, Northwest University, Xi'an 710127, P.R. China
 E-mail: guanzhh@nwu.edu.cn

Green Chem., 2017, Advance Article

DOI: 10.1039/C6GC03137D

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C6GC03137D?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

A novel and facile iron-catalyzed cyclization of ketoxime acetates and aldehydes for the green synthesis of substituted pyridines has been developed. In the presence of a FeCl₃ catalyst, this reaction exhibited a good functional group tolerance to produce 2,4,6-triarylsubstituted symmetrical pyridines in high yields in the absence of any additive. A gram-scale reaction sequence was performed to demonstrate the scaled-up applicability of this synthetic method.

4-Phenyl-2,6-di-p-tolylpyridine (3bb). Yield 70% (47.0 mg); Yellow solid; mp 148-150 o C; S-3

1 H NMR (400 MHz, CDCl3): δ 8.09 (d, J = 8.0 Hz, 4H), 7.82 (s, 2H), 7.72 (d, J = 7.2 Hz, 2H), 7.52-7.45 (m, 3H), 7.31 (d, J = 8.0 Hz, 4H), 2.42 (s, 6H).

13C NMR (100 MHz, CDCl3): δ 157.3, 149.9, 139.2, 138.9, 136.8, 129.4, 129.0, 128.8, 127.1, 126.9, 116.5, 21.3.

HRMS Calcd (ESI) m/z for C25H22N: [M+H] + 336.1747. Found: 336.1731.





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Product Control Using Substrate Design

Product Control Using Substrate Design

New class of cyclic Weinreb amides for oxidative C-H olefination or Heck reaction

Read more

Silver-initiated radical ring expansion/fluorination of ethynyl cyclobutanols: efficient synthesis of monofluoroethenyl cyclopentanones

Silver-initiated radical ring expansion/fluorination of ethynyl cyclobutanols: efficient synthesis of monofluoroethenyl cyclopentanones

Green Chem., 2016, Advance Article
DOI: 10.1039/C6GC02656G, Communication

Qingshan Tian, Bin Chen, Guozhu Zhang
A stereoselective synthesis of [small beta]-halogenated 2-methylenecyclopentanones via silver-catalyzed formal ring expansion using water as the cosolvent is described.

Silver-initiated radical ring expansion/fluorination of ethynyl cyclobutanols: efficient synthesis of monofluoroethenyl cyclopentanones

Qingshan Tian,^a   Bin Chen^a and   Guozhu Zhang*^a  

*

Corresponding authors

^a

State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
E-mail: guozhuzhang@sioc.ac.cn

Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC02656G

A stereoselective synthesis of β-halogenated 2-methylenecyclopentanones via silver-catalyzed formal ring expansion using water as the cosolvent is described. A variety of 2-methylenecyclopentanones with fluoro, chloro and bromo functionalities are efficiently prepared from 1-alkynyl cyclobutanols. This method offers facile access to halogenated complex molecules which are not only useful chemicals but also valuable building blocks for further derivatizations.

1-(m-tolylethynyl)cyclobutan-1-ol (1b) Yield: 89%; Yellow oil;

1H NMR (400 MHz, CDCl3)

δ 7.25 (s, 1H), 7.23 (d, J = 8.1 Hz, 1H), 7.18 (t, J = 7.5 Hz, 1H), 7.10 (d, J = 7.5 Hz, 1H), 2.51 (dt, J = 15.8, 6.3 Hz, 2H), 2.34 (t, J = 9.3 Hz, 2H), 2.30 (s, 3H), 1.85 (m, 2H);

13C NMR (100 MHz, CDCl3)

δ 137.94, 132.27, 129.19, 128.72, 128.17, 122.49, 92.16, 83.58, 68.31, 38.64, 21.20, 12.98; HRMS (EI+ , 70 eV): C13H14O [M]+ : calcd. 186.1045, found 186.1047

(E)-2-(fluoro(phenyl)methylene)cyclopentan-1-one (2a) Yield: 85%; Colorless oil;

1H NMR (400 MHz, CDCl3) δ 7.79 (dd, J = 8.0, 1.5 Hz, 2H), 7.46-7.40 (m, 3H), 2.94 (td, J = 7.3, 3.3 Hz, 2H), 2.43 (td, J = 7.9, 1.2 Hz, 2H),1.99 (m, 2H);

13C NMR (100 MHz, CDCl3) δ 204.7 (d, J = 14.4 Hz), 162.4 (d, J = 270.7 Hz), 131.1, 130.0, 129.7, 128.7 (d, J = 7.0 Hz), 127.8, 117.3 (d, J = 19.4 Hz), 40.7 (d, J = 4.3 Hz), 27.6 (d, J = 3.9 Hz), 19.4;

19F (376 MHz, CDCl3) δ -76.9;

HRMS (EI+ , 70 eV): C12H11FO [M]+ : calcd. 190.0794, found 190.0795.

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Simultaneous rapid reaction workup and catalyst recovery

Simultaneous rapid reaction workup and catalyst recovery

Green Chem., 2016, 18,5769-5772
DOI: 10.1039/C6GC02448C, Communication

Zhichao Lu, Zofia Hetman, Gerald B. Hammond, Bo Xu
By combining reaction work-up and catalyst recovery into a simple filtration procedure we have developed a substantially faster technique for organic synthesis.

By combining reaction work-up and catalyst recovery into a simple filtration procedure we have developed a substantially faster technique for organic synthesis. Our protocol eliminates the time-consuming conventional liquid–liquid extraction and is capable of parallelization and automation. Additionally, it requires only minimal amounts of solvent.

Simultaneous rapid reaction workup and catalyst recovery

Zhichao Lu,^a   Zofia Hetman,^a   Gerald B. Hammond*^a and  Bo Xu*^b  

Hide Affiliations

*

Corresponding authors

^a

Department of Chemistry, University of Louisville, Louisville, USA
E-mail: gb.hammond@louisville.edu

^b

College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Renmin Lu, Shanghai 201620, China
E-mail: bo.xu@dhu.edu.cn

Green Chem., 2016,18, 5769-5772

DOI: 10.1039/C6GC02448C

http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C6GC02448C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

. General procedure for a reaction Step 1. Reaction setup. The reaction is conducted in the usual way with the supported catalyst. Porelite® (typically 1 mL for every 0.1 gram of product) is added to the reaction mixture under stirring, Step 2. Reaction quench and rigid solvent extraction. If needed, the reaction is quenched with a suitable aqueous solution (e.g. NaHCO3 solution). • If the solvent used in the reaction is water-miscible (eg., DMF, methanol, etc.), a minimum amount of water immiscible solvent (e.g. 3 mL ether for every 1 g of product) is added to help organic material become entrenched in Porelite. • If the reaction is conducted in a water immiscible solvent (e.g. toluene, DCM), no extra solvent is needed in most cases. The excess amount of solvent is removed by rotavapor or by nitrogen/air purging (no need to remove the water from the mixture). The reaction mixture is filtered to remove aqueous-soluble components (starting materials, by-products, etc.) and washed with water (or HCl or Na2CO3 solution to remove basic or acidic byproducts. Vacuum is applied to dry the filtrate for 2 minutes to remove any remaining aqueous and volatile solvents. (For automatic flash chromatographic separation, an empty loading cartridge can be used, which can be directly attached to the commercial system. For manual chromatographic separation, a regular Büchner filter can be used). Step 3. Sample loading to chromatographic system. • The loading cartridge can be directly attached to the commercial flash chromatographic system (e.g., CombiFlash Rf series). • For manual chromatographic separation, the polymer powder is loaded directly onto a manual flash silica gel column (dry loading).

Because the polymer pad may contain some trapped air, it is recommended to start with the least polar solvent (e.g., hexane) during chromatographic separation to remove the trapped air.



1-(biphenyl-4-yl)ethanone

1-(biphenyl-4-yl)ethanone

Han, W.; Liu, C.; Jin, Z.-L. Organic Letters 2007, 9, 4005-4007


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