The addition reaction of monomeric lithium enolate (Z)-1, derived from propiophenone, to propene oxide 2, was examined to clarify the exact geometry of the transition state (TS) involved in this type of reaction. The eight possible TSs and the corresponding pathways, four leading to syn γ-hydroxy ketone (γ-HK) 3 and four leading to anti γ-HK 4, were compared, using the B3LYP/6-31+G(d)//B3LYP/6-31+G(d) theory level in vacuo and in the presence of the reaction solvent (toluene/hexane). In every case, the favored pathway involves a TS where the enolate CC and the epoxide C−C are in a gauche relationship and where the Li+ is stabilized by some C−C and C−H σ bonds of epoxide 2.
A DFT Investigation of the Addition Reaction of Monomeric Lithium Enolate Derived from Propiophenone to Propene Oxide: Examination of the Possible Transition Structures
POMELLI, CHRISTIAN SILVIO;BIANUCCI, ANNA MARIA PAOLA;CROTTI, PAOLO;FAVERO, LUCILLA
2004-01-01
Abstract
The addition reaction of monomeric lithium enolate (Z)-1, derived from propiophenone, to propene oxide 2, was examined to clarify the exact geometry of the transition state (TS) involved in this type of reaction. The eight possible TSs and the corresponding pathways, four leading to syn γ-hydroxy ketone (γ-HK) 3 and four leading to anti γ-HK 4, were compared, using the B3LYP/6-31+G(d)//B3LYP/6-31+G(d) theory level in vacuo and in the presence of the reaction solvent (toluene/hexane). In every case, the favored pathway involves a TS where the enolate CC and the epoxide C−C are in a gauche relationship and where the Li+ is stabilized by some C−C and C−H σ bonds of epoxide 2.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
