Asian Journal of Organic Chemistry,
Год журнала:
2023,
Номер
13(1)
Опубликована: Дек. 11, 2023
Abstract
This
study
reports
the
first
synthesis
of
tetrahydroquinaldic
and
tetrahydropicolinic
amides
using
readily
available
quinolines
pyridines
through
dearomative
difunctionalization
hydrolysis
under
transition‐metal‐
reductant‐free
conditions.
The
prepared
amide
products
could
be
easily
oxidized
to
corresponding
quinaldic
picolinic
amides.
Furthermore,
chemical
reactivity
group
has
been
explored
develop
convenient
methods
for
their
conversion
other
common
organic
functional
groups.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(48)
Опубликована: Окт. 11, 2023
A
copper-catalyzed
dearomative
alkynylation
of
pyridines
is
reported
with
excellent
regio-
and
enantioselectivities.
The
synthetically
valuable
enantioenriched
2-alkynyl-1,2-dihydropyridine
products
afforded
are
generated
from
the
readily
available
feedstock,
pyridine,
commercially
terminal
alkynes.
three-component
reaction
between
a
alkyne,
methyl
chloroformate
employs
copper
chloride
StackPhos,
chiral
biaryl
P,N-
ligand,
as
catalytic
system.
Under
mild
conditions,
desired
1,2-addition
delivered
in
up
to
99
%
yield
regioselectivity
ratios
25
:
1
enantioselectivities
values
ee.
Activated
non-activated
alkynes
containing
wide
range
functional
groups
well
tolerated.
Even
acetylene
gas
mono-alkynylated
high
Application
methodology
an
efficient
enantioselective
synthesis
piperidine
indolizidine,
coniceine,
reported.
ACS Catalysis,
Год журнала:
2024,
Номер
14(5), С. 3582 - 3595
Опубликована: Фев. 20, 2024
Selective
cascading
hydroelementation
of
N-heteroarenes
represented
by
pyridines
can
provide
diverse
accesses
to
not
only
dihydro
products
but
also
tetrahydro
and
piperidines
bearing
an
sp3
C–E
bond
(E
=
B,
Si,
etc.).
Herein,
we
describe
the
Co-catalyzed
hydroboration
quinolines
pyridines.
A
precatalyst
Co(acac)2
with
a
P∧N
ligand
(R-Fc-PHOX;
R
tBu,
Ph,
or
iPr)
enabled
stepwise
HBpin
(1
3
equiv)
exclusively
give
1,2-DHQ
C4-borylated
tetrahydroquinolines
in
high
efficiency
(TON
up
2000/[Co]
gram
scale
TOF
500/h).
similar
system
using
monodentate
phosphine
efficiently
catalyzed
regio-
stereoselective
double
furnish
range
1,3-diboryl-1,2,3,4-tetrahydropyridines,
which
were
situ
hydrogenated
corresponding
C–B
β
nitrogen
atom.
Experimental
mechanistic
studies
on
quinoline
suggested
insights
as
follows:
(1)
precursor
active
(P∧N)Co
hydride
species
is
(P∧N)Co(acac)2,
involved
catalyst
initiation
step
induction
period.
(2)
The
first
phase
highly
1,2-selective.
(3)
C(sp3)–B
formation
second
turnover-limiting
overall
catalytic
process.
(4)
under
kinetic
differentiation.
Molbank,
Год журнала:
2023,
Номер
2023(3), С. M1710 - M1710
Опубликована: Авг. 9, 2023
Site-selective
functionalization
of
pyridines
is
a
crucial
tool
for
the
synthesis
diverse
pharmaceuticals
and
materials.
We
introduced
diiminium
pyridine
adducts
as
highly
convenient
potent
Lewis
acids.
report
that
tributylphosphine
selectively
adds
to
4-position
in
tetramethyldiiminium
ditrifluoromethanesulfonate,
resulting
formation
title
compound.
This
finding
represents
an
advancement
towards
utilization
units
organic
reagents
or
catalysts
functionalization.
also
employ
computational
models
determine
fluoride
hydride
ion
affinities,
Fukui
function
f+(r),
molecular
electrostatic
potential,
pKa
values,
providing
valuable
insights
future
investigations
this
area.
Organic Letters,
Год журнала:
2023,
Номер
25(50), С. 8987 - 8991
Опубликована: Дек. 7, 2023
We
report
a
rhodium-catalyzed
asymmetric
addition
of
aryl
and
alkenyl
boronic
acids
to
quinoxalinium
salts
that
generates
dihydroquinoxalines
with
high
enantioselectivity.
Functionalization
the
reaction
products,
dihydroquinoxaline,
allows
preparation
tetrahydroquinoxalines
various
substitution
patterns.
Organic Letters,
Год журнала:
2023,
Номер
25(51), С. 9087 - 9091
Опубликована: Дек. 19, 2023
The
stereoselective
preparation
of
functionalized
[1,2,4]triazolo[4,3-a]pyridines
from
N-tosylhydrazones
and
pyridines
was
developed
through
the
dearomatization
pyridines.
current
transformation
features
good
step-
atom-economy,
high
diastereoselectivity,
efficient
formation
four
new
carbon-heteroatom
bonds
in
corresponding
product
tetrahydro
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(12), С. 8896 - 8905
Опубликована: Июнь 10, 2024
Endocyclic
1-azaallyl
anions
engage
allyl
acetates
in
a
palladium-catalyzed
allylation
followed
by
reduction
to
give
unprotected
2-(hetero)aryl-3-allylpiperidines
and
2-allyl-3-arylmorpholines,
products
not
easily
accessible
other
means.
The
group
is
then
readily
transformed
into
variety
of
functional
groups.
Preliminary
studies
on
the
asymmetric
variant
reaction
using
an
enantiomerically
pure
BI-DIME-type
ligand
provide
product
with
moderate
enantioselectivity.
Computational
suggest
that
energy
barriers
inner-sphere
reductive
elimination
outer-sphere
nucleophilic
substitution
are
almost
same,
which
makes
both
them
possible
pathways.
In
addition,
mechanism
displays
enantiodiscriminating
C–C
bond
forming
step,
while
much
less
selective,
combined
Frontiers in Chemistry,
Год журнала:
2024,
Номер
12
Опубликована: Июнь 7, 2024
Catalytic
hydroboration
and
hydrosilylation
have
emerged
as
promising
strategies
for
the
reduction
of
unsaturated
hydrocarbons
carbonyl
compounds,
well
dearomatization
N-heteroarenes.
Various
catalysts
been
employed
in
these
processes
to
achieve
formation
reduced
products
via
distinct
reaction
pathways
intermediates.
Among
intermediates,
N-silyl
enamines
N-boryl
enamines,
which
are
derived
from
hydroboration,
commonly
underestimated
this
process.
Because
versatile
intermediates
recently
utilized
situ
nucleophilic
reagents
or
dipolarophiles
synthesis
diverse
molecules,
an
expeditious
review
utilization
is
crucial.
In
review,
we
comprehensively
discuss
a
wide
range
used
enamines.
These
include
main-group
metals
(e.g.,
Mg
Zn),
transition
Rh,
Ru,
Ir),
earth-abundant
Fe,
Co,
Ni),
non-metal
(including
P,
B,
organocatalysts).
Furthermore,
highlight
recent
research
efforts
that
leveraged
intriguing
offering
insights
into
future
directions
invaluable
building
blocks.
