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Theoretical study on the mechanism of thieno[3,2‐ b ]benzofuran bromination : the importance of Lewis and non‐Lewis type NBOs interactions along the reaction path
Author(s) -
Vektariene Ausra
Publication year - 2016
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.3483
Subject(s) - chemistry , natural bond orbital , density functional theory , electrophile , computational chemistry , benzofuran , bromine , electrophilic addition , lewis acids and bases , fukui function , electron localization function , stereochemistry , organic chemistry , electron , physics , quantum mechanics , catalysis
A density functional theory study has been performed to estimate the electrophilic thieno[3,2‐ b ]benzofuran bromination reaction. Optimized structures for all stationary points were examined by employing the B3LYP and BMK at the 6‐31++G(d,p), 6‐311G(d,p), and 6‐311++G(d,p) levels of theory. The solvent polarity has a significant effect on a reduction of activation energies barriers. The reaction involves the formation of a triangle complex, migration of a proton through the bromine moiety followed by ionization of the bromine bond, and activation to the σ‐complex. Finally, the σ‐complex transforms into the reaction products. The natural bond orbital (NBO) population analysis was performed along the reaction minimal energy path defined as a function of the intrinsic reaction coordinate (IRC). The evolution of interaction energies between filled and empty NBOs along IRC has been estimated. The importance of these interactions for the disruption of BrBr and CH bonds and creation of CBr and HBr bonds have been emphasized. The changes in NBOs hybridization, covalency effects, electrostatic potential density maps, and occupancy of natural bonds have been investigated along IRC. The results obtained explain well the essence of bonding transformations and electron density changes during the reaction. Copyright © 2015 John Wiley & Sons, Ltd.