Chemistry - A European Journal,
Journal Year:
2019,
Volume and Issue:
25(18), P. 4688 - 4694
Published: Feb. 20, 2019
Abstract
The
chiral
transient
directing
group
(TDG)
strategy
has
been
successfully
introduced
to
the
rhodium(III)‐catalyzed
asymmetric
C−H
activation.
In
presence
of
a
catalytic
amount
amine
and
an
achiral
rhodium
catalyst,
various
phthalides
were
synthesized
from
simple
aldehydes
with
high
chemoselectivity,
regioselectivity,
enantioselectivity
(53
examples,
up
73
%
yield
>99
ee
).
It
is
noteworthy
that
induction
model
different
previously
reported
TDG
system
using
amino
acid
derivatives
palladium
salts.
imino
generated
in
situ
aldehyde
acts
as
monodentate
promote
activation,
stereoselectively
generating
rhodacycle
bearing
metal
center.
Moreover,
stereogenic
center
product
created
stereocontrolled
during
Grignard‐type
addition
C−Rh
bond
aldehyde,
rather
than
activation
step.
Chemical Reviews,
Journal Year:
2020,
Volume and Issue:
120(3), P. 1788 - 1887
Published: Jan. 6, 2020
During
the
past
decades,
synthetic
organic
chemistry
discovered
that
directing
group
assisted
C–H
activation
is
a
key
tool
for
expedient
and
siteselective
construction
of
C–C
bonds.
Among
various
strategies,
bidentate
groups
are
now
recognized
as
one
most
efficient
devices
selective
functionalization
certain
positions
due
to
fact
its
metal
center
permits
fine,
tunable,
reversible
coordination.
The
family
permit
types
assistance
be
achieved,
such
N,N-dentate,
N,O-dentate,
N,S-dentate
auxiliaries,
which
categorized
based
on
coordination
site.
In
this
review,
we
broadly
discuss
bond
reactions
formation
bonds
with
aid
groups.
Angewandte Chemie International Edition,
Journal Year:
2018,
Volume and Issue:
58(25), P. 8304 - 8329
Published: Oct. 12, 2018
Abstract
In
recent
years,
transition‐metal‐catalyzed
C−H
activation
has
become
a
key
strategy
in
the
field
of
organic
synthesis.
Rhodium
complexes
are
widely
used
as
catalysts
variety
functionalization
reactions
because
their
high
reactivity
and
selectivity.
The
availability
number
rhodium
various
oxidation
states
enables
diverse
reaction
patterns
to
be
obtained.
Regioselectivity,
an
important
issue
chemistry,
can
accomplished
by
using
directing
group
assist
reaction.
However,
obtain
target
functionalized
compounds,
it
is
also
necessary
use
that
easily
removed.
A
wide
range
directed
catalyzed
have
been
reported
date.
this
Review,
we
discuss
Rh‐catalyzed
aided
removable
such
phenol,
amine,
aldehyde,
ketones,
ester,
acid,
sulfonic
N‐heteroaromatic
derivatives.
Angewandte Chemie International Edition,
Journal Year:
2020,
Volume and Issue:
59(45), P. 19773 - 19786
Published: July 20, 2020
Abstract
Transition
metal‐catalyzed
enantioselective
functionalization
of
C−H
bond,
the
most
abundant
functionality
in
organic
molecules,
has
emerged
as
an
expedient
synthetic
approach
to
streamline
synthesis
complex
chiral
molecules.
Despite
significant
progress,
traditional
directing
group‐enabled
strategies
require
additional
steps
for
installation
and
removal
groups
from
target
molecule.
The
recently
developed
asymmetric
using
transient
(
c
TDGs)
offers
a
promising
alternative
that
can
circumvent
this
obstacle
therefore
simplify
process.
In
Minireview,
we
briefly
discuss
advent
recent
advances
emerging
concept,
with
emphasis
on
discussing
creation
various
stereogenic
centers
developments
TDGs.
Applications
natural
product
ligand
derivatizations
are
also
discussed.
We
hope
Minireview
will
highlight
great
potential
strategy
help
inspire
further
endeavors.
ACS Catalysis,
Journal Year:
2020,
Volume and Issue:
10(23), P. 13748 - 13793
Published: Nov. 12, 2020
Direct
catalytic
transformation
of
C–H
bonds
to
new
functionalities
has
provided
a
powerful
strategy
synthesize
complex
molecular
scaffolds
in
straightforward
way.
Unstinting
efforts
the
synthetic
community
have
helped
overcome
long-standing
major
challenge
regioselectivity
by
introducing
directing
group
concept.
However,
full
potential
cannot
be
realized
unless
activated
are
stereochemically
controlled.
The
enantioselective
bond
functionalization
could
provide
an
imperative
tool
for
sustainable
way
synthesizing
chiral
scaffolds.
Despite
intrinsic
challenges
achieving
stereocontrol,
developed
different
tools
order
achieve
stereoselective
functionalization.
In
this
review,
we
discuss
remarkable
recent
advances
emerging
area
C(sp2)–H
highlight
and
opportunities,
emphasizing
techniques
so
far.
Chemical Society Reviews,
Journal Year:
2021,
Volume and Issue:
50(9), P. 5517 - 5563
Published: Jan. 1, 2021
Following
notable
cases
of
remarkable
potency
increases
in
methylated
analogues
lead
compounds,
this
review
documents
the
state-of-the-art
C–H
methylation
technology.
Journal of the American Chemical Society,
Journal Year:
2018,
Volume and Issue:
140(51), P. 17884 - 17894
Published: Nov. 30, 2018
L,X-Type
transient
directing
groups
(TDGs)
based
on
a
reversible
imine
linkage
have
emerged
as
broadly
useful
tools
for
C–H
activation
of
ketones
and
free
amines.
However,
competitive
binding
interactions
among
multiple
reaction
components
(TDG
itself,
substrate,
substrate–TDG
adduct)
with
the
palladium
catalyst
often
lead
to
formation
unreactive
complexes,
rendering
ligand
development
extremely
challenging.
Herein,
we
report
finding
versatile
2-pyridone
ligands
that
addresses
these
problems
significantly
improves
γ-methylene
arylation
alkyl
amines,
extending
coupling
partners
wide
range
medicinally
important
heteroaryl
iodides
even
previously
bromides.
The
combination
an
appropriate
group
pyridone
has
also
enabled
δ-arylation
Notably,
our
design
reveals
importance
matching
size
Pd-chelation
different
palladacycles
generated
from
γ-
δ-C–H
bonds:
TDGs
coordinate
Pd(II)
form
six-membered
chelate
are
selective
toward
γ-C–H
bonds,
whereas
via
five-membered
tend
activate
bonds.
These
findings
provide
avenue
developing
protecting
functionalization
using
strategy.
ACS Catalysis,
Journal Year:
2018,
Volume and Issue:
9(1), P. 236 - 241
Published: Nov. 26, 2018
The
visible-light-mediated
three-component
dicarbofunctionalization
of
styrenes
using
simple
benzylic
radicals
is
described.
Notably,
this
work
describes
a
rare
example
undirected
unsubstituted
benzyl
radicals.
Key
to
the
success
strategy
was
rational
design
and
use
pyridinium
salts
as
radical
precursors.
Using
approach,
abundant
styrenes,
electron-rich
heterocycles,
amines
were
combined
rapidly
afford
number
densely
functionalized
1,1-diarylalkanes.
A
dipeptide-derived
salt
applied
in
transformation,
which
resembles
deaminative
generation
from
peptides.
