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[10]annulene: Electrocyclization mechanisms
Author(s) -
Palmeiro Raúl,
Castaño Obis
Publication year - 2021
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.26529
Subject(s) - annulene , azulene , chemistry , yield (engineering) , quantum chemical , limiting , computational chemistry , naphthalene , cis–trans isomerism , double bond , quantum yield , stereochemistry , molecule , photochemistry , thermodynamics , physics , organic chemistry , quantum mechanics , mechanical engineering , engineering , fluorescence
The mechanism of 6‐π electrocyclization of all‐ cis , mono‐ trans , and double‐ trans [10]annulene to yield 4a,8a‐dihydronaphthalene has been explored at various quantum‐chemical methods. The mono‐ trans configuration cyclizes preferentially to trans ‐4a,8a‐dihydronaphthalene, in agreement with the experimental results. The cyclization of the all‐ cis configuration requires firstly a bond‐shifting to the naphthalene‐like conformation of double‐ trans [10]annulene, which is the rate‐limiting step, and finally its azulene‐like conformation electrocyclizes quickly to cis ‐4a,8a‐dihydronaphthalene. Its experimental rate coefficient is consistent with the computed one for the cyclization of the all‐ cis configuration, unlike the calculated one for the double‐ trans configuration. These results confirm the configurations assigned by Masamune et al. to the two isomers which they isolated.