Handbook of CH‐Functionalization,
Год журнала:
2022,
Номер
unknown, С. 1 - 39
Опубликована: Окт. 2, 2022
Abstract
Rhodium
complexes
are
exceptionally
significant
in
homogeneous
catalysis.
The
synthetic
community
observed
the
rapid
burgeoning
of
such
rhodium
catalysis
since
discovery
Wilkinson's
catalyst.
Rhodium‐catalyzed
tandem
C(sp
2
)H/C(sp
3
)H
activation
and
annulation
with
alkenes,
alkynes,
arenes,
other
reactive
partners
is
a
rapidly
growing
research
field
to
obtain
new
class
heterocycles
thereby
generates
potential
biologically
active
pharmacophores.
Superior
reactivity
catalysts
attributed
due
its
good
π‐acceptor
character
that
favors
CH
bond
reaction
substrates
containing
wide
range
directing
groups,
as
amides,
imines,
carboxylic
acid
(derivatives),
benzylic
alcohols,
ketones,
various
shown
efficiency
toward
befitting
partners;
even
undirected
activations
have
also
been
achieved.
This
article
provides
brief
account
recent
developments
rhodium‐catalyzed
activation/annulation
reactions
for
synthesis
classes
fused
cyclic
scaffolds
using
suitable
coupling
partners.
For
strategies,
different
types
cyclization
reactions,
namely,
oxidative,
redox‐neutral,
photoredox,
electrochemical
discussed.
In
addition,
enantioselective
annulated
molecules
chiral
has
highlighted.
Chemical Communications,
Год журнала:
2023,
Номер
59(67), С. 10137 - 10140
Опубликована: Янв. 1, 2023
Selective
annulations
of
alkynes
represent
a
powerful
tool
for
constructing
multicyclic
scaffolds
while
installing
desired
substitution
patterns
with
precision.
Herein,
we
report
Rh-catalyzed
unique
annulation
indolyl
oxopropanenitrile
hydroxy-alkynoates
to
access
pyranoindole
cyclic
motifs,
featuring
enol
oxygen
as
rare
chemoselective
reactive
terminal.
The
reaction
proceeds
via
five-membered
oxy-rodacycle
through
C-H
activation
by
rhodium
complex
guided
enolic-
and
propargyloxy
dual
co-ordination
enable
regio-
stereoselective
modular
assembly.
Organic Letters,
Год журнала:
2021,
Номер
23(20), С. 7888 - 7893
Опубликована: Окт. 6, 2021
Given
their
omnipresence
in
natural
products
and
pharmaceuticals,
isochromenone
congeners
are
one
of
the
most
privileged
scaffolds
to
synthetic
chemists.
Disclosed
herein
is
a
dual
(ortho/meta)
C-H
C-C
activation
phenacyl
ammonium
salts
(acylammonium
as
traceless
directing
group)
toward
annulation
with
propargylic
alcohols
accomplish
rapid
access
for
novel
isochromenones
by
means
rhodium
catalysis
from
readily
available
starting
materials.
This
operationally
simple
protocol
features
broad
substrate
scope
wide
functional
group
tolerance.
Importantly,
circumvents
need
any
stoichiometric
metal
oxidants
proceeds
under
aerobic
conditions.
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(9), С. 6105 - 6114
Опубликована: Апрель 26, 2022
An
effective
rhodium(III)
catalysis
for
the
construction
of
valuable
tetracyclic
compounds
is
described
herein.
This
domino
process
involving
C–H
activation/[3
+
2]
annulation/intramolecular
Friedel–Crafts
reaction
sequences
simple
and
readily
available
N-Boc
hydrazones
propargylic
monofluoroalkynes
afforded
fused
spiro[cyclobutane-1,9′-indeno[1,2-a]indenes]
in
moderate
to
good
yields,
featuring
three
C–C
bond
formation.
Moreover,
control
experiments
indicated
that
activation
might
be
involved
rate-determining
step.
Current Organic Chemistry,
Год журнала:
2022,
Номер
26(16), С. 1575 - 1584
Опубликована: Авг. 1, 2022
Abstract:
In
this
contribution,
an
operationally
simple
and
efficient
synthetic
procedure
for
synthesizing
derivatives
of
4-(arylmethylene)-5-oxo-4,5-dihydroisoxazol-3-yl)acetate
has
been
developed.
This
interesting
protocol
involves
the
one-pot
cyclocondensation
diethyl
3-oxopentanedioate,
aryl
or
heteroaryl
aldehydes,
hydroxylamine
hydrochloride
catalyzed
in
aqueous
medium
using
azolium
salt
as
a
robust
organo-catalyst.
work,
first
time,
1,3-dibenzyl-1H-benzo[d]imidazol-3-ium
chloride
was
used
catalyst
synthesis
ethyl-2-(4-(arylmethylene)-5-oxo-4,5-dihydroisoxazol-3-yl)acetate
from
commercially
available
starting
materials.
Notably,
no
by-products
were
observed
during
multicomponent
reaction.
Optimization
studies
revealed
that
5
mol%
is
sufficient
to
perform
experiment.
Furthermore,
examining
results
temperature
conditions
showed
70
ºC
best
carry
out
optimization
study,
H2O
most
effective
solvent
three-component
cyclization
method,
environmentally
benign
inexpensive
reaction
medium,
so
point
view
it
can
be
said
heterocyclization
obeys
principles
green
chemistry.
several
advantages,
such
good
excellent
yields,
reasonable
times,
isolation
heterocyclic
products
without
column
chromatography
other
chromatographic
methods,
atom-economy,
step-economy,
clean
profiles.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(21), С. 3713 - 3717
Опубликована: Сен. 16, 2023
Abstract
We
herein
disclose
a
simple
and
general
method
for
the
synthesis
of
chromendiones
through
Rh(III)‐catalyzed
C−H
functionalization/annulation
reactions
nitrones
with
cyclic
2‐diazo‐1,3‐diones
by
using
nitrone
group
as
traceless
directing
group.
This
exhibits
high
efficiency
broad
functional
compatibility.
The
derivatization
these
has
been
also
demonstrated
to
further
strengthen
synthetic
utility
transformation.
Organic Chemistry Frontiers,
Год журнала:
2022,
Номер
9(7), С. 1904 - 1910
Опубликована: Янв. 1, 2022
A
Rh(
iii
)-catalysed
external
oxidant
free
C–H
imidization/[4
+
2]
annulation
cascade
has
been
realized
to
deliver
dihydroquinazolin-4(1
H
)-one
derivatives
in
a
one-pot
fashion.
Organic Letters,
Год журнала:
2023,
Номер
25(11), С. 1823 - 1828
Опубликована: Март 16, 2023
A
novel
regioselective
annulation
of
propargylic
alcohols
with
simple
carbazoles
for
the
construction
[3,2,1-jk]carbazole
scaffolds
is
described
to
be
first
example
intermolecular
synthesis
[3,2,1-jk]carbazoles
from
carbazoles.
In
situ
propargyl
simple,
cheap,
and
easily
accessible
ketones
has
also
been
developed
during
one-pot
[3,2,1-jk]carbazoles.
Chemical Communications,
Год журнала:
2022,
Номер
58(79), С. 11099 - 11102
Опубликована: Янв. 1, 2022
A
novel
strategy
for
the
synthesis
of
2-arylethenesulfonyl
fluorides
from
nitrones
and
ethenesulfonyl
fluoride
(ESF)
by
activation
C-H
bond
using
an
inexpensive
readily
available
Ru-catalyst
has
been
developed.
In
this
process,
directing
group
can
be
concomitantly
converted
to
amide
group.
Interestingly,
changing
substituent
nitrogen
a
tert-butyl
methyl
resulted
in
formation
cyclic
isoindolinones.
Detailed
mechanistic
studies
are
also
presented.
Organic & Biomolecular Chemistry,
Год журнала:
2022,
Номер
21(3), С. 651 - 659
Опубликована: Дек. 19, 2022
A
new
synthetic
protocol
has
been
developed
to
construct
polyfunctional
isoxazol-5-one
derivatives
with
imidazole
moiety.
It
is
based
on
the
Knoevenagel
condensation
of
aldehydes
and
subsequent
Michael
addition
N-oxides
as
part
a
tandem
three-component
process.
This
reaction
proceeds
smoothly
in
moderate-to-good
yield
under
catalyst-free
conditions.
Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(70)
Опубликована: Окт. 11, 2023
Although
challenging,
the
distant
C-H
functionalization
with
precision
is
quite
rewarding
and
has
long
been
intriguing.
Tailoring
an
appropriate
template
accomplishes
job
but
prerequisite
sets
limitation.
We
herein
unveil
our
discovery
of
annulation
alkynes
on
to
two
(from
directing
group)
bonds
through
rollover
cyclometallation
assisted
by
conjugated
C=C
bond.
The
follows
a
concomitant
cyclization
rare
triple
functionalization.
totally
regioselective
array
unsymmetrical
alkynes,
taking
leverage
extended
conjugation
or
tertiary
hydroxyl
co-ordination.
mechanism
supported
control
experiments,
KIE
&
labelling
studies
Mass
spectrometry.
