%0 Journal Article
%A Guindon, Yvan
%A Faucher, Anne-Marie
%A Bourque, Élyse
%A Caron, Valérie
%A Jung, Grace
%A Landry, Serge R.
%D 1997
%T The Exocyclic Effect: Protecting Group Strategy to Enhance
Stereoselectivity in Hydrogen Transfer Reactions of Acyclic Free
Radicals
%U https://acs.figshare.com/articles/journal_contribution/The_Exocyclic_Effect_Protecting_Group_Strategy_to_Enhance_Stereoselectivity_in_Hydrogen_Transfer_Reactions_of_Acyclic_Free_Radicals/3708183
%R 10.1021/jo971595s.s001
%2 https://acs.figshare.com/ndownloader/files/5798730
%K acyclic substrates
%K stereogenic center α
%K diastereoselectivity
%K Exocyclic
%K Strategy
%K feasibility
%K hydrogen transfer reaction
%K steric
%K R 1
%K strategy
%K discrimination
%K diol
%K Acyclic Free Radicals
%K factor
%K substituent
%K rationale
%K bifunctional
%K Hydrogen Transfer Reactions
%K Enhance Stereoselectivity
%K exocyclic radicals
%K analysis
%K Protecting
%K transition state models
%X To enhance the diastereoselectivity of the hydrogen transfer
reaction of acyclic substrates bearing
1,2- or 1,3-diols, the feasibility of a strategy employing bifunctional
protecting groups has been
demonstrated. This strategy is based upon the “exocyclic
effect” or the significant improvement of
anti-selectivity exhibited by the reductions of substrates
in which the two substituents (R1 and Y)
at the stereogenic center α to the radical center are linked
together. A rationale for the excellent
facial discrimination of these exocyclic radicals is offered
based on an analysis of transition state
models, which considers both steric and electronic
factors.
%I ACS Publications