Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(19), P. 3544 - 3548
Published: May 9, 2022
Herein,
chiral
Brønsted
acid-catalyzed
intramolecular
asymmetric
allylic
alkylation
of
indoles
with
primary
alcohols
is
described.
The
allyl
were
directly
employed
as
the
precursors
in
this
metal-free
protocol,
without
preactivation
or
any
additional
activating
reagents.
This
method
provides
convenient
synthesis
a
broad
range
functionalized
tetrahydrocarbazoles
excellent
yields
(≤97%)
good
enantioselectivity
(≤93%
ee).
optimal
conditions
are
compatible
for
gram-scale
reaction.
Molecules,
Journal Year:
2025,
Volume and Issue:
30(2), P. 428 - 428
Published: Jan. 20, 2025
A
series
of
α-hydroxy-alkylphosphonates
and
α-hydroxy-alkylphosphine
oxides
were
synthesized
by
the
Pudovik
reaction
acetaldehyde
acetone
with
dialkyl
phosphites
or
diarylphosphine
oxides.
The
additions
performed
in
three
different
ways:
liquid
phase
using
triethylamine
as
catalyst
(1),
on
surface
Al2O3/KF
solid
(2),
a
MW-assisted
Na2CO3-catalyzed
procedure
(3).
In
most
cases,
our
methods
more
efficient
robust
than
those
applied
literature.
Two
subjected
to
single-crystal
X-ray
analysis,
suggesting
dimeric
chain
supramolecular
buildup
their
respective
crystals.
Four
one
α-hydroxy-ethylphosphine
oxide
reacted
acid
chlorides
afford
ten
α-acyloxyphosphonates.
Diethyl
α-hydroxy-ethylphosphonate
was
transformed
methanesulfonyloxy
derivative
that
useful
Michaelis–Arbuzov
triethyl
phosphite
ethyl
diphenylphosphinite
tetraethyl
ethylidenebisphosphonate
diethyl
α-(diphenylphosphinoyl)-ethylphosphonate,
respectively.
α-hydroxyphosphonates
α-hydroxyphosphine
prepared
bioactivity
studies,
compounds
tested
exhibited
limited
cytotoxic
effects
U266
cells
modest
reductions
viability
at
concentration
100
μM.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
14(7), P. 1912 - 1918
Published: Dec. 23, 2022
Vinyl-substituted
alcohols
represent
a
highly
useful
class
of
molecular
skeletons.
The
current
method
typically
requires
either
stoichiometric
metallic
reagents
or
preformed
precursors.
Herein,
we
report
nickel
catalysis-enabled
synthesis
vinyl-substituted
via
5-membered
oxa-metallacycle.
In
this
protocol,
acetylene,
the
simplest
alkyne
and
abundant
feedstock,
is
employed
as
an
ideal
C2
synthon.
reaction
features
mild
conditions,
good
functional
group
tolerance
broad
substrate
scope.
Mechanistic
exploration
implies
that
oxa-metallacycle
originated
from
cyclometallation
aldehyde
acetylene
key
intermediate
for
transformation,
which
then
terminated
by
silane-mediated
σ-bond
metathesis
subsequent
reductive
elimination.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(9), P. 1970 - 1974
Published: Feb. 29, 2024
A
well-defined
tridentate
chiral
sulfoxide-N-olefin
ligand
has
been
designed
and
applied
in
rhodium-catalyzed
asymmetric
allylic
substitutions
of
racemic
carbonates,
providing
the
branched
products
good
yields
with
to
high
enantioselectivities
excellent
regioselectivities.
This
reaction
mechanism,
which
involves
possible
hemilability
olefin
coordination
on
hybrid
ligands
rhodium,
is
elaborated
as
well.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(27), P. 5646 - 5651
Published: July 2, 2024
The
development
of
site-selective
and
regio-
enantioselective
reactions
substrates
with
multiple
active
sites
is
an
important
topic
remains
a
substantial
challenge
in
synthetic
chemistry.
Here,
we
describe
rhodium-catalyzed
asymmetric
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 12, 2024
Enantioenriched
unnatural
amino
acids
represent
a
prevalent
motif
in
organic
chemistry,
with
profound
applications
biochemistry,
medicinal
and
materials
science.
Herein,
we
report
cobalt-catalyzed
aza-Barbier
reaction
of
dehydroglycines
unactivated
alkyl
halides
to
afford
α-amino
esters
high
enantioselectivity.
This
catalytic
reductive
alkylative
addition
protocol
circumvents
the
use
moisture-,
air-sensitive
organometallic
reagents,
stoichiometric
chiral
auxiliaries,
enabling
conversion
variety
primary,
secondary,
even
tertiary
α-alkyl-amino
under
mild
conditions,
thus
leading
broad
functional
group
tolerance.
The
expedient
access
biologically
active
motifs
demonstrates
practicality
this
by
reducing
number
synthetic
steps
enhancing
efficiency.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(20), P. 3693 - 3697
Published: May 15, 2023
A
highly
regio-
and
enantioselective
allylic
sulfonylation
has
been
developed
with
rhodium
bisoxazolinephosphine
(NPN*)
ligands
from
racemic
branched
carbonates
readily
available
sulfonyl
hydrazides
under
neutral
conditions.
Branch-selective
sulfones
a
>20:1
branch:linear
ratio
>99%
ee
could
be
synthesized
in
≤96%
yield.
Both
Z
E
linear
also
converted
into
the
same
chiral
high
enantioselectivities.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(52)
Published: Oct. 28, 2022
An
iridium-catalyzed
asymmetric
synthesis
of
branched
allylic
phosphine
compounds
under
mild
conditions
is
reported.
Products
bearing
various
functional
groups
can
be
synthesized
with
excellent
stereoselectivity
(up
to
99.9
%
ee)
and
regioselectivity.
The
employment
sulfides
relatively
low
deactivation
capacity
against
metal
catalysts
crucial
for
the
success
this
reaction.
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(8), P. 5482 - 5490
Published: April 7, 2023
Abnormal
Claisen
rearrangement
of
phenyl
allyl
ether
with
the
γ-alkyl
group
is
longstanding.
However,
asymmetric
version
this
named
reaction
has
never
been
reported.
Herein,
a
highly
regio-
and
enantioselective
allylic
alkylation
4-hydroxycoumarin
stereospecific
Conia-ene/ene
sequence
developed
as
formal
abnormal
rearrangement.
Chiral
4-hydroxycoumarins
3-allyl
groups
could
be
synthesized
in
up
to
95%
yield
96%
ee
under
catalysis
Rh
chiral
bioxazolinephosphine
ligand.
Experimental
density
functional
theory
calculation
investigations
support
that
based
on
reversible
formation
kinetically
favored
cis-disubstituted
spirocyclopropane
intermediate.
Organic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(12), P. 2976 - 2987
Published: Jan. 1, 2023
DFT
calculations
reveal
an
inner-sphere
C–N
reductive
elimination
pathway
for
the
cobalt/bisoxazolinephosphine-catalyzed
allylic
substitution
of
racemic
carbonates
with
amines.
