Monday 26 December 2016

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 Wanga 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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Friday 2 December 2016

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

Sunday 6 November 2016

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 Chena 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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Friday 28 October 2016

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  
*
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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A catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles: an easy access to five-ring-fused tetrahydroisoquinolines





A catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles: an easy access to five-ring-fused tetrahydroisoquinolines

Green Chem., 2016, Advance Article
DOI: 10.1039/C6GC02517J, Communication
Xihong Liu, Dongxu Yang, Kezhou Wang, Jinlong Zhang, Rui Wang
A catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles has been reported under mild conditions.


A catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles: an easy access to five-ring-fused tetrahydroisoquinolines

Xihong Liu,a   Dongxu Yang,a   Kezhou Wang,a  Jinlong Zhanga and   Rui Wang*ab  
*
Corresponding authors
a
School of Life Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou 730000, P. R. China
E-mail: wangrui@lzu.edu.cn
b
State Key Laboratory of Chiroscience, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, P. R. China
E-mail: bcrwang@polyu.edu.hk
Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC02517J































We have reported herein a catalyst-free 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines and 3-nitroindoles by which a series of five-ring-fused tetrahydroisoquinolines featuring an indoline scaffold were obtained as single diastereomers in moderate to high yields without any additives under mild conditions. Moreover, the current method provides a novel and convenient approach for the efficient incorporation of two biologically important scaffolds (tetrahydroisoquinoline and indoline).


ethyl 13b-nitro-8-tosyl-8,8a,13b,13c-tetrahydro-5H-indolo[2',3':3,4]pyrazolo[5,1- a]isoquinoline-9(6H)-carboxylate






ethyl 13b-nitro-8-tosyl-8,8a,13b,13c-tetrahydro-5H-indolo[2',3':3,4]pyrazolo[5,1- a]isoquinoline-9(6H)-carboxylate:
White solid, m.p. 153 – 154 oC; 94% yield; 1H NMR (300 MHz, CDCl3) δ 7.86 (d, J = 8.2 Hz, 2H), 7.78 (d, J = 7.9 Hz, 1H), 7.30 – 7.13 (m, 5H), 7.1 (s, 1H), 7.05 – 6.94 (m, 1H), 6.94 – 6.87 (m, 1H), 6.59 (t, J = 7.6 Hz, 3H), 6.28 (d, J = 7.6 Hz, 1H), 4.78 (s, 1H), 4.37 (q, J = 7.1 Hz, 2H), 2.80 – 2.58 (m, 2H), 2.33 (s, 3H), 2.31 – 2.11 (m, 2H), 1.41 (t, J = 7.1 Hz, 3H) ppm;

13C NMR (75 MHz, CDCl3) δ 152.1, 144.6, 142.6, 134.0, 132.1, 129.3, 129.0, 128.7, 128.3, 127.5, 127.3, 126.2, 122.8, 121.1, 115.5, 104.5, 84.9, 70.7, 62.8, 48.5, 29.1, 21. 6, 14.3 ppm;

HRMS (ESI): C27H26N4NaO6S [M + Na]+ calcd: 557.1465, found: 557.1476.


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Friday 14 October 2016

Register Today for the ACS Symposium in India on Recent Advances in Drug Development, 11-12 November 2016 in Hyderabad, India

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Inaugural ACS Industry Symposium, 11-12 November 2016 in Hyderabad, India

Recent Advances in Drug Development

Register Today for the ACS Symposium in India on Recent Advances in Drug Development
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Register now for the inaugural ACS Industry Symposium, 11-12 November 2016 in Hyderabad, India. Be sure to secure your seat today as rates will increase on 27 October!
The theme of the Symposium is Recent Advances in Drug Development. The event will feature lectures by the world's leading researchers and experts in the pharma industry, including:
  • Dr. Peter Senter of Seattle Genetics
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  • Dr. Ming-Wei Wang of the Shanghai Institute of Materia Medica, Chinese Academy of Sciences
This is an exclusive event being organized in partnership with Dr. Reddy's Laboratories for pharma professionals throughout India. Space is limited so register today!
Please visit our website to learn more about the speakers and the program.
Register today to ensure your access to the ACS Industry Symposium. We look forward to seeing you in Hyderabad in November.
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