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DFT studies on the cascade rearrangement reactions of the cubylcarbinyl radical
Author(s) -
Zhang QingLi,
Chen BoZhen
Publication year - 2011
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1720
Subject(s) - chemistry , reaction rate constant , radical ion , radical cyclization , computational chemistry , radical , transition state theory , cascade , photochemistry , basis set , reaction mechanism , free radical reaction , density functional theory , medicinal chemistry , kinetics , organic chemistry , ion , catalysis , physics , quantum mechanics , chromatography
DFT (U)B3LYP calculations with the 6‐311 + G** basis set were carried out to investigate the mechanisms of cascade rearrangement reactions (involving eight reaction channels) of the cubylcarbinyl radical (radical 1 ). The rate constant for each reaction step was calculated on the basis of the conventional transition state theory. The reaction channel from radical 1 to the 4‐(4‐methylenecyclobut‐2‐enyl) radical is preferred kinetically, while the reaction channel from radical 1 to the 1‐homocubyl radical is unfavorable. The mechanism of the conversion from radical 1 to the tricyclic dienes radical, which is experimentally uncertain, is predicted to be a stepwise process with the methylenesecocubyl radical as an intermediate instead of a concerted reaction. The energy barrier and rate constant of the initial reaction step are evaluated to be 2.8 kcal/mol and 3.0 × 10 10 s −1 , respectively, in excellent agreement with the corresponding experimental values. Copyright © 2010 John Wiley & Sons, Ltd.