Advanced Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 25, 2024
The
development
of
efficient
methodologies
for
the
controlled
manufacture
specific
stereoisomers
bearing
quaternary
stereocenters
has
prompted
advances
in
a
variety
scientific
disciplines
including
pharmaceutical
chemistry,
materials
science,
and
chemical
biology.
However,
complete
control
absolute
relative
stereochemical
configurations
alkyne
derivatives
remains
an
unmet
synthetic
challenge.
Herein,
Ni/Cu
dual-catalyzed
asymmetric
propargylic
substitution
reaction
is
presented
to
produce
propargylated
products
with
all-carbon
high
yields
significant
diastereo-
enantioselectivities
(up
>20:1
dr,
>99%
ee).
synthesis
all
variants
methohexital,
widely
used
sedative-hypnotic
drug,
exemplifies
efficacy
stereodivergent
propargylation.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(22), P. 3965 - 3969
Published: May 31, 2022
The
first
catalytic
enantioselective
[3
+
2]
cycloaddition
reaction
between
vinylcyclopropanes
and
alkenyl
N-heteroarenes
in
the
presence
of
LiBr
a
Pd(0)/SEGPHOS
complex
was
developed.
plays
key
role
improving
reactivity
as
mild
Lewis
acid.
The Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
88(12), P. 7651 - 7659
Published: Sept. 15, 2022
Chiral
O–N–N
tridentate
ligands
were
designed
from
proline
and
BINOL.
Their
design
strategy
performance
evaluated
using
a
copper(II)-catalyzed
asymmetric
Henry
reaction
as
model.
The
desired
β-nitroalcohols
obtained
in
up
to
94%
ee's.
Preliminary
results
suggested
that
the
stereofacial
selection
of
reactions
was
mainly
controlled
by
chiral
diamine
moiety
derived
proline,
matching
central
axial
chiralities
essential
for
high
stereoselectivity
reaction.
Enantioswitching
observed
when
an
appropriate
substituent
introduced
binaphthyl
group.
Si-selections
found
2a
without
3-substituents
ligand,
Re-selections
with
same
enantioselectivities
2i
bearing
3-trifluoromethyl
group
used
ligand.
Inorganic Chemistry,
Journal Year:
2024,
Volume and Issue:
63(14), P. 6285 - 6295
Published: March 22, 2024
Isomerization
of
epoxides
into
versatile
allylic
alcohols
is
an
atom-economical
synthetic
method
to
afford
vicinal
bifunctional
groups.
Comprehensive
density
functional
theory
(DFT)
calculations
were
carried
out
elucidate
the
complex
mechanism
a
bimetallic
Ti/Co-catalyzed
selective
isomerization
allyl
by
examining
several
possible
pathways.
Our
results
suggest
involving
(1)
radical-type
epoxide
ring
opening
catalyzed
Cp2Ti(III)Cl
leading
Ti(IV)-bound
β-alkyl
radical,
(2)
hydrogen-atom
transfer
(HAT)
Co(II)
catalyst
form
Ti(IV)-enolate
and
Co(III)–H
intermediate,
(3)
protonation
give
alcohols,
(4)
proton
abstraction
Co(I)
species
followed
electron
regenerate
active
Ti(III)
species.
Moreover,
catalysis
two-state
reactivity
enable
key
rate-determining
HAT
step.
Furthermore,
subtle
balance
between
dispersion-driven
processes
entropy-driven
monometallic
determines
most
favorable
pathway,
among
which
process
energetically
more
in
all
steps
except
vital
study
should
provide
in-depth
mechanistic
understanding
catalysis.
Advanced Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 25, 2024
The
development
of
efficient
methodologies
for
the
controlled
manufacture
specific
stereoisomers
bearing
quaternary
stereocenters
has
prompted
advances
in
a
variety
scientific
disciplines
including
pharmaceutical
chemistry,
materials
science,
and
chemical
biology.
However,
complete
control
absolute
relative
stereochemical
configurations
alkyne
derivatives
remains
an
unmet
synthetic
challenge.
Herein,
Ni/Cu
dual-catalyzed
asymmetric
propargylic
substitution
reaction
is
presented
to
produce
propargylated
products
with
all-carbon
high
yields
significant
diastereo-
enantioselectivities
(up
>20:1
dr,
>99%
ee).
synthesis
all
variants
methohexital,
widely
used
sedative-hypnotic
drug,
exemplifies
efficacy
stereodivergent
propargylation.
