178180-80-8Relevant articles and documents
Resolution of diols via catalytic asymmetric acetalization
Kim, Ji Hye,ori, Ilija,Palumbo, Chiara,List, Benjamin
, p. 1778 - 1781 (2015)
A highly enantioselective kinetic resolution of diols via asymmetric acetalization has been achieved using a chiral confined imidodiphosphoric acid catalyst. The reaction is highly efficient for the resolution of tertiary alcohols, giving selectivity factors of up to >300. Remarkably, even in cases where the selectivity factors are only moderate, highly enantioenriched diols are obtained via a stereodivergent resolution to diastereomeric acetals.
Reactivity and selectivity in the oxidation of styrene derivatives, II studies on the oxidation of p-substituted α-methylstyrenes
Suprun, Wladimir
, p. 231 - 237 (2007/10/03)
The liquid phase oxidation of p-substituted (Br-, Cl-, t-Bu-, MeO-, CF3-) α-methylstyrenes and of α,p-dimethoxystyrene with pure oxygen was investigated in chlorobenzene solution and in presence of cumene and of cumene hydroperoxide in the temperature range 65-125°C. The product yields were determined gaschromatographically. The differences of the activation energies of the epoxide formation and the parallel reactions amount to 19-48 kJ/mol. The epoxide selectivity increases with increasing temperature and concentration of olefine. The relative chain propagation constants kp (C=C) were determined by competitive oxidation with cumene. The kp(C=C) values of p-substituted α-methylstyrenes can be correlated by the Hammett equation with both σ and σ+ substituent constants.
