Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 11, 2024
Chiral
2-azetines
and
allenes
are
highly
valuable
structural
units
in
natural
products
useful
chemicals.
However,
enantioselective
synthesis
of
both
has
been
extremely
challenging.
Herein,
we
present
asymmetric
construction
chiral
(70-98
%
yields
up
to
96
ee)
through
phosphine-catalyzed
[2+2]
annulation
yne-enones
with
sulfamate-derived
cyclic
imines.
These
were
easily
transformed
into
upon
treatment
Et
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(11), P. 7419 - 7430
Published: March 6, 2024
The
first
earth-abundant
transition
metal
Ni-catalyzed
highly
regio-
and
enantioselective
semihydrogenation
of
racemic
tetrasubstituted
allenes
via
a
kinetic
resolution
process
as
challenging
task
was
well
established.
This
protocol
furnishes
expedient
access
to
diversity
structurally
important
enantioenriched
chiral
allylic
molecules
with
high
regio-,
enantio-,
Z/E-selectivity.
Remarkably,
this
proceeded
one
carbon–carbon
double
bond
allenes,
which
regioselective
complementary
the
Rh-catalyzed
asymmetric
version.
Deuterium
labeling
experiments
density
functional
theory
(DFT)
calculations
were
carried
out
reveal
reasonable
reaction
mechanism
explain
regio-/stereoselectivity.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(11), P. 7173 - 7177
Published: March 6, 2024
In
recent
years,
remarkable
progress
has
been
described
in
the
development
of
methods
that
simultaneously
control
vicinal
stereochemistry,
wherein
both
stereochemical
elements
are
central
chirality;
contrast,
and
axial
chirality
comparatively
rare.
Herein
we
report
a
chiral
nickel
catalyst
achieves
enantioconvergent
diastereoselective
coupling
racemic
secondary
alkyl
electrophiles
with
prochiral
1,3-enynes
(in
presence
hydrosilane)
to
generate
tetrasubstituted
allenes
bear
an
adjacent
stereogenic
center.
A
carbon–carbon
carbon–hydrogen
bond
formed
this
process,
which
provides
good
stereoselectivity
is
compatible
array
functional
groups.
Organic Chemistry Frontiers,
Journal Year:
2024,
Volume and Issue:
11(9), P. 2477 - 2484
Published: Jan. 1, 2024
A
variety
of
optically
active
tertiary
propargylic
alcohols
and
tetrasubstituted
2,3-allenoic
acids
have
been
synthesized
via
a
Pd((
R
)-DTBM-SEGphos)Cl
2
-catalyzed
carboxylative
kinetic
resolution
reaction
racemic
alcohols.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(39), P. 7263 - 7267
Published: Sept. 27, 2023
An
electroreductive
cross-coupling
of
prop-2-yn-1-yl
acetates
with
chloro(vinyl)silanes
for
producing
tetrasubstituted
silylallenes
is
developed.
The
method
enables
the
formation
a
new
C─Si
bond
through
cathodic
reduction
silyl
radical,
radical
addition
across
C≡C
bond,
alkenyl
anion
intermediate
formation,
and
deacetoxylation
represents
mild,
practical
route
to
synthesis
silylallenes.
Mechanistic
studies
reveal
that
CoCl2
acts
as
mediator
promote
via
electron
transfer.
European Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
27(30)
Published: March 22, 2024
Abstract
Allenes
represent
a
distinctive
class
of
organic
molecules
characterized
by
their
unique
physical
and
chemical
properties.
Among
them,
chiral
allenes
play
significant
role
in
modern
chemistry.
They
not
only
serve
as
pivotal
frameworks
for
natural
products
drug
but
also
are
essential
building
blocks
synthesis.
Over
the
years,
numerous
remarkable
efficient
methods
have
been
developed
synthesis
allenes.
Notably,
catalytic
using
transition
metals
conjunction
with
ligands
has
garnered
considerable
attention.
This
review
paper
aims
to
provide
an
overview
recent
advancements
through
asymmetric
1,4‐difunctionalization
1,3‐enynes,
which
two
distinct
strategies
including
non‐radical
radical
processes
highlighted.
Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(39)
Published: May 7, 2024
Axially
chiral
cycloalkylidenes
are
interesting
but
less
developed
axially
molecules.
Here,
a
bispidine-based
amine
catalytic
system
was
to
promote
efficiently
the
asymmetric
Knoevenagel
condensation
of
N-protected
oxindoles
and
benzofuranones
with
4-substituted
cyclohexanones.
A
variety
alkylidenecycloalkanes
stable
axial
chirality
were
obtained
in
good
yields
fairly
er
(enantiomeric
ratio).
Based
on
absolute
configuration
determination
product
DFT
calculations,
possible
mechanism
stereoselective
induction
proposed.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(25), P. 9703 - 9708
Published: Jan. 1, 2024
A
palladium-catalyzed
asymmetric
[4
+
3]
cycloaddition
of
the
methylene-trimethylenemethane
donor
with
an
azadiene
has
been
developed,
affording
benzofuro[3,2-
b
]azepine-derived
exocyclic
chiral
allene
control
axial
and
point
chirality.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 27, 2024
Abstract
Radical‐involved
arylative
cross‐coupling
reactions
have
recently
emerged
as
an
attractive
strategy
to
access
valuable
aryl‐substituted
motifs.
However,
there
still
exist
several
challenges
such
limited
scope
of
radical
precursors/acceptors,
and
lack
general
asymmetric
catalytic
systems,
especially
regarding
the
multicomponent
variants.
Herein,
we
reported
a
copper‐Box
system
for
three‐component
vinylarenes
1,3‐enynes,
with
oxime
carbonates
aryl
boronic
acids.
The
proceed
under
practical
conditions
in
absence
or
presence
visible‐light
irradiation,
affording
chiral
1,1‐diarylalkanes,
benzylic
alkynes
allenes
good
enantioselectivities.
Mechanistic
studies
imply
that
copper/Box
complexes
play
dual
role
both
generation
ensuing
cross‐coupling.
In
cases
irradiation
could
improve
activity
complex
toward
initial
generation,
enabling
better
efficiency
match
between
formation
