Kinetics and mechanism of the phase-transfer-catalyzed carbonylation of benzyl bromide by cobalt tetracarbonyl anion

1983 ◽  
Vol 2 (12) ◽  
pp. 1730-1736 ◽  
Author(s):  
Herve Des Abbayes ◽  
Anne Buloup ◽  
Guy Tanguy
Keyword(s):  
Phase Transfer ◽  
Benzyl Bromide ◽  
Kinetics And Mechanism

scholarly journals Microwave-Assisted Improved Regioselective Synthesis of 12H-Benzopyrano[3,2-c][1]benzopyran-5-ones by Radical Cyclisation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Pradipta Kumar Basu ◽  
Amrita Ghosh
Keyword(s):  
Microwave Irradiation ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Benzyl Bromide ◽  
Catalytic Amount ◽  
Ammonium Bromide ◽  
Catalysis Condition ◽  
Microwave Assisted ◽  
Tributyltin Hydride ◽  
Tetrabutyl Ammonium

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.

Kinetics and mechanism of reaction of benzyl bromide with copper in dimethylacetamide

2005 ◽  
Vol 18 (5) ◽  
pp. 456-461 ◽  
Author(s):  
Anatoly M. Egorov ◽  
Svetlana A. Matyukhova ◽  
Alexander V. Anisimov
Keyword(s):  
Benzyl Bromide ◽  
Kinetics And Mechanism ◽  
Mechanism Of Reaction
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