First examples of intramolecular addition of primary amidyl radicals to olefins

2005 ◽  
Vol 83 (6-7) ◽  
pp. 543-545 ◽  
Author(s):  
Philippe Gaudreault ◽  
Christian Drouin ◽  
Jean Lessard
Keyword(s):  
Key Words ◽  
Nitrogen Heterocycles ◽  
Catalytic Amount ◽  
Radical Cyclization ◽  
Tributyltin Hydride

The first examples of intramolecular addition of primary amidyl radicals to olefins are described. Amidyl radicals were generated from N-(phenylthio)amides in refluxing benzene using a catalytic amount of 2,2′-azobis(isobutyronitrile) (5 mol%) and tributyltin hydride (~2.2 equiv.). The resulting yields of cyclic products ranged from 63% to 85%.Key words: radical cyclization, amidyl radicals, nitrogen heterocycles.

Intramolecular Radical Cyclization of Vinyl, Aryl and Alkyl Halides Using Catalytic Amount of Bis-tri-n-butyltin Oxide/Sodium Borohydride: A Novel Entry to Functionalized Carbocycles

Synlett ◽  
2015 ◽  
Vol 26 (08) ◽  
pp. 1055-1058 ◽  
Author(s):  
Namasivayam Palani ◽  
Sengottuvelan Balasubramanian ◽  
Tarur Dinesh
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Amount ◽  
Radical Cyclization ◽  
Alkyl Halides ◽  
Cyclization Reactions

We wish to report a facile method in which a catalytic amount of bis-tri-n-butyltinoxide (TBTO) in the presence of sodium borohydride efficiently brings about the intramolecular radical cyclization of a variety of vinyl, aryl and alkyl halides to their corresponding functionalized bicyclic and tricyclic carbocycle frameworks. The methodology obviates the need for stoichiometric amounts of tin reagent normally required for radical cyclization reactions.

Aryl Radical Cyclization of Chiral 3-Allyl-2-(2-bromophenyl)-1,3-oxazolidines with Tributyltin Hydride

Heterocycles ◽  
2002 ◽  
Vol 58 (1) ◽  
pp. 431 ◽  
Author(s):  
Kimio Higashiyama ◽  
Takayasu Yamauchi ◽  
Jumpei Sugiyama
Keyword(s):  
Radical Cyclization ◽  
Aryl Radical ◽  
Tributyltin Hydride

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.

scholarly journals Oxidation of p-Aminophenols and Formal Radical Cyclization onto Benzene Rings: Formation of Benzo-Fused Nitrogen Heterocycles.

ChemInform ◽  
2005 ◽  
Vol 36 (18) ◽  
Author(s):  
Stephen P. Fletcher ◽  
Derrick L. J. Clive ◽  
Jianbiao Peng ◽  
David A. Wingert
Keyword(s):  
Nitrogen Heterocycles ◽  
Radical Cyclization ◽  
Benzene Rings

ChemInform Abstract: Catalytic Use of Organostannyl Radical: The Reaction of 1,2,3-Selenadiazole with Olefins in the Presence of a Catalytic Amount of Tributyltin Hydride.

ChemInform ◽  
2010 ◽  
Vol 30 (45) ◽  
pp. no-no
Author(s):  
Yutaka Nishiyama ◽  
Yasunobu Hada ◽  
Masahiro Anjiki ◽  
Sakiko Hanita ◽  
Noboru Sonoda
Keyword(s):  
Catalytic Amount ◽  
Tributyltin Hydride
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