Premium
Ab initio studies of three‐membered ring formation through intramolecular nucleophilic substitution
Author(s) -
Han InSuk,
Kim Chang Kon,
Kim Chan Kyung,
Lee BonSu,
Lee Ikchoon
Publication year - 1997
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/(sici)1096-987x(19971115)18:14<1773::aid-jcc6>3.0.co;2-h
Subject(s) - chemistry , intramolecular force , single bond , enthalpy , nucleophilic substitution , heteroatom , computational chemistry , ab initio , ring (chemistry) , electronic correlation , bond energy , bond length , double bond , ab initio quantum chemistry methods , crystallography , stereochemistry , molecule , thermodynamics , group (periodic table) , medicinal chemistry , crystal structure , physics , organic chemistry , polymer chemistry
Three‐membered ring (3MR) forming processes of − X(SINGLE BOND)CH 2 (SINGLE BOND)CH 2 (SINGLE BOND)F and − CH 2 (SINGLE BOND)C((SINGLE BOND)Y)(SINGLE BOND)CH 2 (SINGLE BOND)F (X(DOUBLE BOND)CH 2 , O, or S and Y(DOUBLE BOND)0 or S) through a gas phase neighboring group mechanism (S N i ) are studied theoretically using the ab initio molecular orbital method with the 6–31+G* basis set. When electron correlation effects are considered, the activation (Δ G ≠ ) and reaction energies (Δ G 0 ) are lowered by ca. 10 kcal mol −1 , indicating the importance of the electron correlation effect in these reactions. The contribution of entropy of activation (− T Δ S ≠ ) at 298 K to Δ G ≠ is very small, and the reactions are enthalpy controlled. The Δ G ≠ and Δ G 0 values for these ring closure processes largely depend on the stabilities of the reactants and the heteroatom acting as a nucleophilic center. The Bell–Evans–Polanyi principle applies well to all these reaction series. © 1997 John Wiley & Sons, Inc. J Comput Chem 18 : 1773–1784, 1997