Showing posts with label Water. Show all posts
Showing posts with label Water. Show all posts

Saturday 7 January 2017

Copper-catalyzed S-methylation of sulfonyl hydrazides with TBHP for the synthesis of methyl sulfones in water

Copper-catalyzed S-methylation of sulfonyl hydrazides with TBHP for the synthesis of methyl sulfones in water

Green Chem., 2017, 19,112-116
DOI: 10.1039/C6GC03142K, Communication
Yu Yang, Yajie Bao, Qianqian Guan, Qi Sun, Zhenggen Zha, Zhiyong Wang
A copper-catalyzed S-methylation of sulfonyl hydrazides with TBHP for the synthesis of methyl sulfones in water.

A copper-catalyzed S-methylation of sulfonyl hydrazides with TBHP was efficiently developed, providing a variety of methyl sulfones with good to excellent yields. The reaction can be carried out in water smoothly without any ligand or additive under mild conditions and this catalyst-in-water can be recycled several times.

Copper-catalyzed S-methylation of sulfonyl hydrazides with TBHP for the synthesis of methyl sulfones in water

Yu Yang,a   Yajie Bao,a   Qianqian Guan,a   Qi Sun,a  Zhenggen Zhaa and   Zhiyong Wang*a  
*
Corresponding authors
a
Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Soft Matter Chemistry and Department of Chemistry & Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei, P. R. China
 E-mail: zwang3@ustc.edu.cn
Fax: (+86) 551-360-3185
Green Chem., 2017,19, 112-116

DOI: 10.1039/C6GC03142K
























General procedures for the synthesis of Arylsulfonyl Hydrazides Arylsulfonyl hydrazides 2b-2s were prepared according to the literature procedure.[1] To a solution of an arylsulfonyl chloride (3.0 mmol) in tetrahyrdofuran (15 mL), was added hydrazine monohydrate (375 mg, 7.5 mmol) dropwise under nitrogen at 0 °C. After vigorous stirring for 30 min at 0 °C, the reaction mixture was added ethyl acetate (60 mL), and washed with saturated brine (3 x 10 mL). The organic layer was dried over sodium sulfate, filtered, concentrated and added to hexane (12 mL) over 5 min. The mixture was filtered, and the collected solid was dried in vacuum.


1-methyl-4-(methylsulfonyl)benzene (3aa).[1] The title compound was prepared according to the general procedure and purified by column chromatography (Petroleum Ether: EtOAc = 3:1) to give a white solid (88 % yield).

1H NMR (400 MHz, CDCl3): 7.84-7.82 (d, 2H, J = 8.0 Hz), 7.38- 7.36 (d, 2H, J = 8.0 Hz ), 3.04 (s, 3H), 2.46 ( s, 3H );

13C NMR (100 MHz, CDCl3): 144.7, 137.7, 130.0, 127.3, 44.6, 21.6

Reference [1] G. Yuan, J. Zheng, X. Gao, X. Li, L. Huang, H. Chen and H. Jiang, Chem. Commun., 2012, 48, 7513.


1H NMR (400 MHz, CDCl3): 7.84-7.82 (d, 2H, J = 8.0 Hz), 7.38- 7.36 (d, 2H, J = 8.0 Hz ), 3.04 (s, 3H), 2.46 ( s, 3H );



13C NMR (100 MHz, CDCl3): 144.7, 137.7, 130.0, 127.3, 44.6, 21.6




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Friday 29 July 2016

Water and n-Butyllithium Together At Last

Water and n-Butyllithium Together At Last







Cycloaddition of nitrone ylides with aldehydes using catalytic amounts of nBuLi

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Saturday 9 April 2016

Microbial cyclosophoraose as a catalyst for the synthesis of diversified indolyl 4H-chromenes via one-pot three component reactions in water



  • Green Chem., 2016, Advance Article
    DOI: 10.1039/C6GC00137H, Paper
    Someshwar D. Dindulkar, Daham Jeong, Eunae Cho, Dongjin Kim, Seunho Jung
    A novel biosourced saccharide catalyst, microbial cyclosophoraose, a cyclic [small beta]-(1,2) glucan, was used for the synthesis of indolyl 4H-chromenes via a one pot three-component Knoevenagel-Michael addition-cyclization reaction in water under neutral conditions.


Microbial cyclosophoraose as a catalyst for the synthesis of diversified indolyl 4H-chromenes via one-pot three component reactions in water


 http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C6GC00137H?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Microbial cyclosophoraose as a catalyst for the synthesis of diversified indolyl 4H-chromenes via one-pot three component reactions in water

*
Corresponding authors
a
Institute for Ubiquitous Information Technology and Applications (UBITA) & Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 143-701, South Korea 
E-mail: shjung@konkuk.ac.kr
b
Nelson Mandela African Institution of Science and Technology, PO box 447, Arusha, Tanzania
c
Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, Seoul 143-701, South Korea
Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC00137H




















 As a novel biosourced saccharide catalyst, microbial cyclosophoraose, a cyclic β-(1,2) glucan, was used for the synthesis of therapeutically important versatile indolyl 4H-chromenes via a one pot three-component Knoevenagel–Michael addition–cyclization reaction of salicylaldehyde, 1,3-cyclohexanedione/dimedone, and indoles in water under neutral conditions. A possible reaction mechanism through molecular complexation is suggested based on 2D ROESY NMR spectroscopic analysis. Moreover, green chemistry metric calculations were carried out for a model reaction, indicating the satisfactory greener approach of this method, with a low E-factor (0.18) and high atom economy (AE = 91.20%). The key features of this protocol are based on two critical factors where the first is to use a novel eco-friendly supramolecular carbohydrate catalyst and the second is its fine green properties such as compatibility with various substituted reactants, recyclability of the catalyst, chromatography-free purification, high product selectivity, and clean conversion with moderate to excellent yields in an aqueous medium.



 9-(1H-indol-3-yl)-5-methoxy-3,3- dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one (4a):


 (2-hydroxy-3-methoxybenzaldehyde 1, Dimedone 2








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Friday 15 May 2015

Ruthenium-Based Water Oxidation Catalyst



Ruthenium-Based Water Oxidation Catalyst

Non-innocent ligand frameworks for promoting multi-electron reactions
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http://www.chemistryviews.org/details/ezine/7705501/Ruthenium-Based_Water_Oxidation_Catalyst.html

  • Author: Claire D'Andola
  • Published Date: 12 May 2015
  • Source / Publisher: Chemistry – A European Journal/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Markus Kärkäs, Rong-Zhen Liao, Björn Åkermark, and co-workers, Stockholm University, Sweden, and Huazhong University of Science and Technology, Wuhan, China, provide an insight into this mechanistic process by using a dinuclear Ru-based WOC.













 Stockholm University, Sweden

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Stockholm University
University in Stockholm, Sweden