The tautomerization and ring closure in the Claisen rearrangement: A DFT study

2018 ◽  
Vol 118 (18) ◽  
pp. e25677
Author(s):  
Shinichi Yamabe ◽  
Shoko Yamazaki
Keyword(s):  
Claisen Rearrangement ◽  
Ring Closure ◽  
Dft Study

Ferrocenyl pyrazolines: Preparation, structure, redox properties and DFT study on regioselective ring-closure

2009 ◽  
Vol 694 (26) ◽  
pp. 4185-4195 ◽  
Author(s):  
Virág Zsoldos-Mády ◽  
Oliver Ozohanics ◽  
Antal Csámpai ◽  
Veronika Kudar ◽  
Dávid Frigyes ◽  
...  
Keyword(s):  
Redox Properties ◽  
Ring Closure ◽  
Dft Study

Gosteli−Claisen Rearrangement: DFT Study of Substituent−Rate Effects

2009 ◽  
Vol 74 (11) ◽  
pp. 4336-4342 ◽  
Author(s):  
Julia Rehbein ◽  
Martin Hiersemann
Keyword(s):  
Claisen Rearrangement ◽  
Dft Study ◽  
Rate Effects

scholarly journals A convenient method for the preparation of cyclohepta[b]indole derivatives

2012 ◽  
Vol 10 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Katalin Kupai ◽  
Gergely Banoczi ◽  
Gabor Hornyanszky ◽  
Pal Kolonits ◽  
Lajos Novak
Keyword(s):  
Convenient Method ◽  
Claisen Rearrangement ◽  
Ring Closure ◽  
Indole Derivatives ◽  
Intramolecular Ring

AbstractCyclohepta[b]indole derivatives 7 were prepared by subsequent aza-Claisen rearrangement and intramolecular ring-closure of (cycloheptenylmethyl)benzenamine (3). The mechanisms of the reactions are also discussed.

scholarly journals [Co(TPP)]-Catalyzed Formation of Substituted Piperidines

2019 ◽  
Author(s):  
Bas de Bruin ◽  
Marianne Lankelma ◽  
Astrid M. Olivares
Keyword(s):  
Radical Cyclization ◽  
Ring Closure ◽  
Radical Formation ◽  
Dft Study ◽  
Powerful Method ◽  
Radical Intermediates ◽  
Benzyl Radical ◽  
Mechanistic Understanding ◽  
High Yields

Radical cyclization via cobalt(III)–carbene radical intermediates is a powerful method for the synthesis of (hetero)cycles. Building on the recently reported synthesis of N-heterocyclic pyrrolidines catalyzed by Co(II) porphyrins, we herein report the [Co(TPP)]-catalyzed formation of desirable six membered N heterocyclic piperidines, directly from linear aldehydes. Piperidines were obtained in overall high yields, with linear alkenes being formed as side products in small amounts. A DFT study was performed to gain a deeper mechanistic understanding of the cobalt(II)-porphyrin-catalyzed formation of pyrrolidines, piperidines and linear alkenes. The calculations show that the alkenes are unlikely to be formed through 1,2-HAT. Instead, the calculations are consistent with a pathway involving benzyl radical formation followed by radical rebound ring-closure to form the piperidines. Competitive 1,5-HAT from the beta-position to the benzyl radical explains the formation of linear alkenes.<br>

scholarly journals [Co(TPP)]-Catalyzed Formation of Substituted Piperidines

2019 ◽  
Author(s):  
Bas de Bruin ◽  
Marianne Lankelma ◽  
Astrid M. Olivares
Keyword(s):  
Radical Cyclization ◽  
Ring Closure ◽  
Radical Formation ◽  
Dft Study ◽  
Powerful Method ◽  
Radical Intermediates ◽  
Benzyl Radical ◽  
Mechanistic Understanding ◽  
High Yields

Radical cyclization via cobalt(III)–carbene radical intermediates is a powerful method for the synthesis of (hetero)cycles. Building on the recently reported synthesis of N-heterocyclic pyrrolidines catalyzed by Co(II) porphyrins, we herein report the [Co(TPP)]-catalyzed formation of desirable six membered N heterocyclic piperidines, directly from linear aldehydes. Piperidines were obtained in overall high yields, with linear alkenes being formed as side products in small amounts. A DFT study was performed to gain a deeper mechanistic understanding of the cobalt(II)-porphyrin-catalyzed formation of pyrrolidines, piperidines and linear alkenes. The calculations show that the alkenes are unlikely to be formed through 1,2-HAT. Instead, the calculations are consistent with a pathway involving benzyl radical formation followed by radical rebound ring-closure to form the piperidines. Competitive 1,5-HAT from the beta-position to the benzyl radical explains the formation of linear alkenes.<br>

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