A Chiral Nanohoop as Highly Efficient Asymmetric Organocatalyst
Published: Aug. 19, 2024
Chiral
phosphoric
acids
are
privileged
organocatalysts
that
have
been
shown
to
facilitate
a
large
variety
of
asymmetric
transformations.
In
recent
years,
the
BINOL
scaffold
has
equipped
with
aromatic
groups
and
transformed
into
dimeric
imidodiphosphates
im-prove
both
chiral
induction
catalyst
turnover
by
tuning
pKa
creating
confined
space
around
catalytic
center.
this
work,
we
report
an
alternative
approach
for
achieving
such
confinement
effect
within
cavity
chiral,
shape-persistent
“carbon
nanohoop”
mac-rocycle.
We
integrated
BINOL-derived
acid
[9]cycloparaphenylene
(CPP)
employed
nanohoop
as
organocatalyst
transfer
hydrogenation
quinolines.
found
macrocycle
shows
excellent
activity
near-quantitative
yields
enantioselectivities
up
96%
ee,
which
is
far
supe-rior
comparable
non-cyclic
reference
catalysts.
While
scope
quinolines
bearing
substituents
wide,
made
counterintuitive
observation
macrocyclic
not
active
smaller
alkyl-substituted
substrates,
indicates
highly
spe-cific
non-covalent
effects
determine
reaction
outcome
cavity.
These
results
suggest
outstanding
selectivities
can
be
achieved
endowing
only
supramolecular
binding
sites
but
also
unusual
topologies.
Language: Английский
Preparation and evaluation of a 1,1′-bi-2-naphthol-based chiral macrocycle bonded silica chiral stationary phase for high performance liquid chromatography
Liqin Yu,
No information about this author
Ruixue Liang,
No information about this author
Juan Chen
No information about this author
et al.
Journal of Chromatography A,
Journal Year:
2024,
Volume and Issue:
1732, P. 465231 - 465231
Published: Aug. 9, 2024
Language: Английский
A Chiral Nanohoop as Highly Efficient Asymmetric Organocatalyst
Published: Aug. 12, 2024
Chiral
phosphoric
acids
are
privileged
organocatalysts
that
have
been
shown
to
facilitate
a
large
variety
of
asymmetric
transformations.
In
recent
years,
the
BINOL
scaffold
has
equipped
with
aromatic
groups
and
transformed
into
dimeric
imidodiphosphates
im-prove
both
chiral
induction
catalyst
turnover
by
tuning
pKa
creating
confined
space
around
catalytic
center.
this
work,
we
report
an
alternative
approach
for
achieving
such
confinement
effect
within
cavity
chiral,
shape-persistent
“carbon
nanohoop”
mac-rocycle.
We
integrated
BINOL-derived
acid
[9]cycloparaphenylene
(CPP)
employed
nanohoop
as
organocatalyst
transfer
hydrogenation
quinolines.
found
macrocycle
shows
excellent
activity
near-quantitative
yields
enantioselectivities
up
96%
ee,
which
is
far
supe-rior
comparable
non-cyclic
reference
catalysts.
While
scope
quinolines
bearing
substituents
wide,
made
counterintuitive
observation
macrocyclic
not
active
smaller
alkyl-substituted
substrates,
indicates
highly
spe-cific
non-covalent
effects
determine
reaction
outcome
cavity.
These
results
suggest
outstanding
selectivities
can
be
achieved
endowing
only
supramolecular
binding
sites
but
also
unusual
topologies.
Language: Английский