scholarly journals Dynamics of the Reaction of 2,4,6-tribromophenol and Benzyl Bromide by Phase Transfer Catalysis.

1993 ◽  
Vol 26 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Maw-Ling Wang ◽  
Yu-Ming Hsieh
2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Pradipta Kumar Basu ◽  
Amrita Ghosh

Two new effective methodologies have been adopted for the preparation of 4-(2′-bromobenzyloxy)benzopyran-7-ones 3(a–h). In the first methodology, 4-hydroxy[1]benzopyran-2-ones 1(a–d) was alkylated with 2-bromobenzyl bromide 2a or 2-bromo-5-methoxy benzyl bromide 2b under phase transfer catalysis condition using lithium hydroxide/tetrabutyl ammonium bromide in N,N-dimethylformamide at 40–50°C and in the second method the microwave irradiation protocol has been exploited by simply mixing of 4-hydroxy[1]benzopyran-2-ones 1(a–d) with 25% excess of 2-bromobenzyl bromide 2a or 2-bromo-5-methoxy benzyl bromide 2b. A catalytic amount of TBAB and potassium carbonate were added and irradiated in an open Erlenmeyer flask in a microwave oven for 4–10 min. The tributyltin-hydride-mediated radical cyclisation of 3(a–h) was carried out under microwave irradiation to generate 12H-benzopyrano[3,2-c][1]benzopyran-5-ones 4(a–h) in 78–88% yield and in this technique yields were significantly improved and reaction time was shortened compared to the previously reported conventional radical cyclisation method.


2009 ◽  
Vol 6 (7) ◽  
pp. 529-534 ◽  
Author(s):  
Istvan Greiner ◽  
Fanni Sypaseuth ◽  
Alajos Grun ◽  
Eva Karsai ◽  
Gyorgy Keglevich

2020 ◽  
Vol 17 (4) ◽  
pp. 405-411
Author(s):  
Chuan-Hui Wang ◽  
Chen-Fu Liu ◽  
Guo-Wu Rao

Oxidation reactions have emerged as one of the most versatile tools in organic chemistry. Various onium salts such as ammonium, phosphonium, arsonium, bismuthonium, tellurium have been used as phase transfer catalysts in many oxidation reactions. Certainly, considerable catalysts have been widely used in Phase-Transfer Catalysis (PTC). This review focuses on the application of PTC in various oxidation reaction. Furthermore, PTC also conforms to the concept of “Green Chemistry”. <p></p> • Oxidation has become one of the most widely used tools in organic chemistry and phase transfer catalysts has been widely used in oxidation. <p></p> • The application of phase transfer catalysts in oxidation reaction will be summarized. <p></p> • Phase transfer catalysts have important application in various oxidation reaction.


2015 ◽  
Vol 27 (9) ◽  
pp. 3208-3210
Author(s):  
Xinqi Liu ◽  
Jia Wang ◽  
Songfang Zhao ◽  
Guoqin Hu

ChemInform ◽  
2010 ◽  
Vol 24 (34) ◽  
pp. no-no
Author(s):  
T. N. VASILEVSKAYA ◽  
E. P. PLOTNIKOVA ◽  
V. S. KOBRIN

Sign in / Sign up

Export Citation Format

Share Document