25112-82-7Relevant articles and documents
Enantioselective desymmetrizing palladium catalyzed carbonylation reactions: The catalytic asymmetric synthesis of quaternary carbon center containing 1,3-dienes
Byrne, Simon J.,Fletcher, Anthony J.,Hebeisen, Paul,Willis, Michael C.
supporting information; experimental part, p. 758 - 760 (2010/06/20)
A desymmetrization protocol has been used to develop a palladium catalyzed enantioselective carbonylation process. Achiral cyclic bis-alkenyltriflates are converted to their corresponding monoester derivatives with selectivities of up to 96% ee. The Royal
Resonance energy of diradicals - 1,8-naphthoquinodimethane
Roth, Wolfgang R.,Unger, Christian,Wasser, Thorsten
, p. 2155 - 2169 (2007/10/03)
From the racemization of 19c and the temperature and NO dependence of the trapping rate of 20b between 218 and 288°C the energy profile for the equilibrium 19b ? 20b is derived. The singlet-triplet splitting of the diradical is 2.5 kcal · mol-1 with the triplet being the ground state. By comparison of the experimental reaction enthalpy with the analogous value for 25, 26 or a hypothetical model reaction with non-interacting radicals it is shown that the stabilizing interaction of the radicals in the singlet state of 20b is negligible making the stabilization of the triplet equivalent to the singlet-triplet splitting. By using literature data it is shown by an analogous analysis that the interaction of the radicals in the bisallyl diradical 28 and in the triplet state of the trimethylenmethane derivative 29 is also negligible whereas in the singlet state of 29 the interaction is strongly destabilizing. VCH Verlagsgesellschaft mbH, 1996.
SYNTHESIS OF ENANTIOMERICALLY PURE (10R, 11S)-(+)-JUVENILE HORMONES I AND II
Mori, Kenji,Fujiwhara, Mitsuhiko
, p. 343 - 354 (2007/10/02)
Enantiomerically pure (+)-juvenile hormone I18JH=JH I> and (+)-juvenile hormone II 17 JH=JH II> were synthesized employing the enantioselective reduction of 2-ethyl-2-methyl-1,3-cyclohexanedione by a yeast (Pichia terricola KI0117) as the key step.