Cu-Catalyzed Hydroboration of Benzylidenecyclopropanes:
Reaction Optimization, (Hetero)Aryl Scope, and Origins of Pathway
Selectivity
Jose M. Medina
Taeho Kang
Tuğçe
G. Erbay
Huiling Shao
Gary M. Gallego
Shouliang Yang
Michelle Tran-Dubé
Paul F. Richardson
Joseph Derosa
Ryan T. Helsel
Ryan L. Patman
Fen Wang
Christopher P. Ashcroft
John F. Braganza
Indrawan McAlpine
Peng Liu
Keary M. Engle
10.1021/acscatal.9b03557.s002
https://acs.figshare.com/articles/dataset/Cu-Catalyzed_Hydroboration_of_Benzylidenecyclopropanes_Reaction_Optimization_Hetero_Aryl_Scope_and_Origins_of_Pathway_Selectivity/10274801
The
copper-catalyzed hydroboration of benzylidenecyclopropanes,
conveniently accessed in one step from readily available benzaldehydes,
is reported. Under otherwise identical reaction conditions, two distinct
phosphine ligands grant access to different products by either suppressing
or promoting the cyclopropane opening via β-carbon elimination.
Computational studies provide insight into how the rigidity and steric
environment of these different bis-phosphine ligands influence the
relative activation energies of β-carbon elimination versus
protodecupration from the key benzylcopper intermediate. The method
tolerates a wide variety of heterocycles prevalent in clinical and
preclinical drug development, giving access to valuable synthetic
intermediates. The versatility of the tertiary cyclopropylboronic
ester products is demonstrated through several derivatization reactions.
2019-11-08 14:43:51
phosphine ligands grant access
reaction conditions
copper-catalyzed hydroboration
Hetero
activation energies
Scope
benzylidenecyclopropane
rigidity
cyclopropane opening
Pathway Selectivity
cyclopropylboronic ester products
steric environment
versatility
intermediate
benzylcopper
β- carbon elimination
benzaldehyde
Cu-Catalyzed Hydroboration
insight
Origins
protodecupration
derivatization reactions
bis-phosphine ligands influence
heterocycle
Computational studies
variety
method
Reaction Optimization
drug development
Benzylidenecyclopropane