Green Synthesis and Catalysis,
Journal Year:
2023,
Volume and Issue:
5(4), P. 324 - 328
Published: Nov. 14, 2023
C(sp2)-H
amination
represents
an
attractive
approach
for
the
synthesis
of
enamines,
which
is
intrinsically
associated
with
challenge
controlling
stereochemistry
and
primarily
relying
on
transition-metal
catalysis.
Herein,
a
metal-free
α-substituted
styrenes
has
been
achieved,
leading
to
stereodivergent
formation
both
E-
Z-enamines
in
50%∼97%
yield
under
mild
conditions
by
using
PhI(OAc)2
as
green
oxidant
ortho-phenylenediamines
nitrogen
source.
Interestingly,
Z/E
selectivity
can
be
controlled
readily
switching
reaction
medium.
E-isomers
were
formed
preferentially
THF,
whereas
n-hexane
favored
Z-isomers.
Preliminary
mechanistic
studies
suggested
that
situ
ortho-benzoquinone
diimides
are
key
intermediates,
there
correlation
between
solvent
polarity
stereoselectivity.
This
study
enriches
chemical
repertoire
particularly
respect
sustainable
amination.
Chemical Society Reviews,
Journal Year:
2024,
Volume and Issue:
53(3), P. 1068 - 1089
Published: Jan. 1, 2024
Leveraging
light
energy
to
expose
the
‘dark’
reactive
states
describes
whole
essence
of
triplet–triplet
transfer.
This
offers
an
impressive
opportunity
conduct
a
multitude
diverse
reactions
and
access
sought-after
molecular
motifs.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(39), P. 27196 - 27203
Published: Sept. 17, 2024
The
functionalization
of
C-H
bonds
streamlines
the
synthesis
complex
molecules
by
eliminating
need
for
substrate
preactivation.
Traditionally,
Kharasch-Sosnovsky
reaction,
which
directly
oxidizes
allylic
into
esters
under
copper
catalysis,
has
been
hampered
long
reaction
times,
limited
scope,
and
low
enantioselectivity
with
acyclic
olefins.
Herein,
we
present
a
novel,
visible
light-driven,
copper-catalyzed
asymmetric
that
overcomes
these
challenges.
This
method
expands
scope
to
include
internal
alkenes
improves
conditions
using
eco-friendly
light
catalysis.
It
enhances
radical
reactivity
achieves
superior
regioselectivity
in
producing
acyloxylation
products.
breakthrough
significantly
advances
direct
techniques,
offering
more
efficient
sustainable
approach
synthesizing
chiral
molecules.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(24)
Published: April 20, 2023
Abstract
Kinetic
resolution
is
a
powerful
strategy
for
the
isolation
of
enantioenriched
compounds
from
racemic
mixtures,
and
development
selective
catalytic
processes
an
active
area
research.
Here,
we
present
nickel‐catalyzed
kinetic
α‐substituted
unconjugated
carbonyl
alkenes
via
enantio‐,
diastereo‐,
regioselective
hydroamination.
This
protocol
affords
both
chiral
butenamides
syn
‐β
2,3
‐amino
acid
derivatives
with
high
enantiomeric
purity
(up
to
99
%
ee)
selectivity
factor
up
>684.
The
key
excellent
efficiency
distinctive
architecture
nickel
complex,
which
enables
successful
enantioselective
C−N
bond
construction.
Mechanistic
investigations
reveal
that
unique
structure
ligand
facilitates
rapid
migratory
insertion
step
one
enantiomer.
provides
practical
versatile
approach
prepare
wide
range
compounds.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(7), P. 5305 - 5313
Published: March 26, 2024
Over
the
past
few
decades,
Narasaka–Heck-type
difunctionalization
of
tethered
alkenes
has
emerged
as
a
powerful
strategy
to
produce
heterocyclic
scaffolds.
However,
asymmetric
synthesis
rarely
been
explored.
Herein,
we
report
robust
palladium-catalyzed
enantioselective
Narasaka–Heck
cyclization–Sonogashira
reaction
alkene-tethered
oxime
esters
and
terminal
alkynes.
By
employing
new
Ming-Phos
ligand,
obtain
high
yields
pyrrolines
with
quaternary
stereocenter
enantioselectivities
under
mild
conditions.
Density
functional
theory
(DFT)
study
reveals
weak
interaction
between
aromatic
ring
substrate
fragment
naphthyl
group
in
which
probably
accounts
for
stereoselectivity.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(43), P. 12143 - 12151
Published: Jan. 1, 2023
We
report
a
selective
and
stereodivergent
three-component
carboallylation
of
terminal
alkynes
with
allylic
carbonates
alkyl
trifluoroborates
via
metallaphotoredox
catalysis
pyrene
as
triplet
energy
transfer
(EnT)
modulator.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(25), P. 5232 - 5236
Published: June 13, 2024
Herein,
we
present
an
efficient
and
practical
kinetic
resolution
(KR)
of
racemic
allylic
pyrazoles
utilizing
photoexcited
chiral-copper-complex-mediated
alkene
E
→
Z
isomerization.
This
method
enables
the
synthesis
both
enantioenriched
E-
Z-allylic
pyrazoles,
achieving
enantiomeric
excesses
(e.e.)
up
to
97%
selectivity
factors
(S
factors)
as
high
217.
Remarkably,
method's
ability
furnish
with
Z-configuration,
which
is
notably
arduous
obtain
under
thermodynamic
control,
underscores
transformative
potential
this
synthetic
protocol.
Advanced Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 5, 2024
A
Pd-catalyzed
enantioselective
aminosilylation
of
alkenes
via
tandem
Aza-Heck/silylation
reaction
under
Pd/Sadphos
catalysis
is
disclosed.
wide
array
oxime
esters
and
silicon
reagents
are
tolerated,
furnishing
the
chiral
pyrrolines
bearing
one
quaternary
or
two
contiguous
stereocenters
in
good
yield
with
high
enantioselectivity.
Not
only
terminal
but
also
tri-substituented
internal
successfully
participate
reaction,
delivering
vicinal
complete
diastereoselectivity
DFT
study
conducted
to
probe
pathway
origin
enantioselectivity,
which
revealed
that
stereoinduction
arises
from
weak
interaction
between
aromatic
ring
substrate
fragment
naphthyl
group
ligand.
Organic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(13), P. 3401 - 3428
Published: Jan. 1, 2023
This
review
summarizes
the
advances
in
field
of
intramolecular
kinetic
resolution
(KR)
mediated
by
non-enzymatic
catalysts.
The
relative
classification
KR
is
accomplished
and
several
categories
reactions
are
discussed.
