3 research outputs found
Selective C–C and C–H Bond Activation/Cleavage of Pinene Derivatives: Synthesis of Enantiopure Cyclohexenone Scaffolds and Mechanistic Insights
The continued development of transition-metal-mediated
C–C
bond activation/cleavage methods would provide even more opportunities
to implement novel synthetic strategies. We have explored the RhÂ(I)-catalyzed
C–C activation of cyclobutanols resident in hydroxylated derivatives
of pinene, which proceed in a complementary manner to the C–C
bond cleavage that we have observed with many traditional electrophilic
reagents. Mechanistic and computational studies have provided insight
into the role of C–H bond activation in the stereochemical outcome
of the Rh-catalyzed C–C bond activation process. Using this
new approach, functionalized cyclohexenones that form the cores of
natural products, including the spiroindicumides and phomactin A,
have been accessed
L'Écho : grand quotidien d'information du Centre Ouest
20 février 19371937/02/20 (A66).Appartient à l’ensemble documentaire : PoitouCh
Zirconocene-Mediated Selective C–C Bond Cleavage of Strained Carbocycles: Scope and Mechanism
Several
approaches using organozirconocene species for the remote
cleavage of strained three-membered ring carbocycles are described.
ω-Ene polysubstituted cyclopropanes, alkylidenecyclopropanes,
ω-ene spiro[2.2]Âpentanes, and ω-ene cyclopropyl methyl
ethers were successfully transformed into stereodefined organometallic
intermediates, allowing an easy access to highly stereoenriched acyclic
scaffolds in good yields and, in most cases, excellent selectivities.
DFT calculations and isotopic labeling experiments were performed
to delineate the origin of the obtained chemo- and stereoselectivities,
demonstrating the importance of microreversibility