om7b00812_si_002.xyz (66.21 kB)
Baldwin-Type Rules for Metal-Controlled Intramolecular Migratory Insertions. A Computational Study of Ni, Pd, and Pt Case
dataset
posted on 2018-01-16, 20:45 authored by Béla Fiser, Juan M. Cuerva, Enrique Gómez-BengoaTransition metal
(Ni, Pd, Pt) promoted carbocyclizations of alkenes
and alkynes have been computationally investigated to rationalize
the easiness or difficulty of such processes depending on the size
of the forming ring. Special emphasis has been placed on measuring
the activation barriers and the exo versus endo selectivities of the processes. The study leads us
to propose some qualitative rules for metal controlled ring closures,
noting some discrepancies with the classical Baldwin’s rules
for nonmetallic cyclizations. Also, some unexpected results were found,
like the extremely low activation barriers for 3-exo-dig and 3-exo-trig closures, contrasting with the
scarcity of such experimental procedures, which can be computationally
interpreted by the reversibility and endergonicity of cyclopropane/cyclopropene
ring formation in the presence of these metals. The consistency of
the present rules has been further checked by introduction of selected
structural variations in the substrates.