Ortho effect in the Bergman cyclization: electronic and steric effects in hydrogen abstraction by 1-substituted naphthalene 5,8-diradicals.
We present a detailed theoretical study of geometries, electronic structure, and energies of transition states and intermediates completing the full Bergman cycloaromatization pathway of ortho-substituted enediynes with a focus on polar and steric contributions to the kinetics and thermodynamics of hydrogen abstraction. This study provides a rare unambiguous example of remote substitution that affects reactivity of a neutral reactive intermediate through an sigma framework.
Department of Chemistry, Hamilton College, Clinton, New York 13323, USA.
Frank C
FC
Pickard
Rebecca L
RL
Shepherd
Amber E
AE
Gillis
Meghan E
ME
Dunn
Steven
S
Feldgus
Karl N
KN
Kirschner
George C
GC
Shields
Mariappan
M
Manoharan
Igor V
IV
Alabugin
D003500:Cyclization; D004581:Electronics; D053281:Enediynes / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D007700:Kinetics; D008956:Models, Chemical; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D013816:Thermodynamics
D053281:Enediynes; D005609:Free Radicals; D009281:Naphthalenes; C031721:naphthalene; D006859:Hydrogen