The
avermectins
make
up
a
biologically
relevant
class
of
complex
natural
products
that
continue
to
inspire
the
development
new
strategies
in
chemical
synthesis.
Herein,
we
disclose
concise
synthesis
southern
core
avermectin
aglycon.
key
hydrobenzofuran
was
forged
by
either
reductive
cyclization
or
cycloisomerization,
both
using
cationic
palladium
precatalyst.
This
hydropalladation
strategy
generated
hydrofuran
ring
under
mild
conditions,
enabling
rapid
construction
tetra-substituted
carbon
stereocenter.
The Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 12, 2025
This
study
explores
the
roles
of
halide
ligands
and
external
electric
fields
(EEFs)
in
tuning
reactivity
cobalt-catalyzed
oxidative
cyclometalation
(OCM)
1,6-enynes,
focusing
on
concerted
mechanism.
Using
density
functional
theory
(DFT),
we
investigate
how
these
factors
influence
key
processes
OCM
step,
particularly
cleavage
π
bonds,
formation
M-C
creation
a
new
C-C
bond.
Our
findings
show
that
polar
solvents
lower
activation
barriers,
while
increase
them,
inhibiting
reaction
by
weakening
back-donation
reducing
orbital
overlap.
However,
strategic
application
EEFs
counteracts
this
inhibition,
enhancing
electron
back-donation,
stabilizing
transition
state,
facilitating
bond
formation.
The
Dewar-Chatt-Duncanson
(DCD)
model,
distortion/interaction
analysis,
quantum
atoms
molecules
(QTAIM)
delocalization
index
(DI)
calculation
reveal
reduce
cobalt
center,
π-back-donation
raising
energy
barriers.
work
provides
insights
into
electronic
geometric
can
be
manipulated
to
optimize
catalytic
performance
synthetic
transformations.
ACS Catalysis,
Год журнала:
2024,
Номер
14(7), С. 4951 - 4957
Опубликована: Март 18, 2024
We
report
the
enantioselective
construction
of
all-carbon
quaternary
stereocenters
(up
to
99%
ee)
by
cationic
Rh(I)/Segphos-catalyzed
hydroalkenylative
cyclization
1,6-enynes
with
α-substituted
acrylamides.
This
Rh
catalysis
proceeds
small
excesses
alkenes
at
room
temperature
in
most
substrates
yield
desired
products
high
yields
and
enantioselectivity.
Mechanistic
studies
indicate
acrylamide-substituted
C–H
bond
activation
processes:
for
acrylamides,
is
cleaved
a
Rh(III)
complex
(rhodacyclopentene);
contrast,
β-substituted
Rh(I)
complex.
Organic Letters,
Год журнала:
2024,
Номер
26(27), С. 5614 - 5619
Опубликована: Июль 2, 2024
Although
various
types
of
asymmetric
cyclization
reactions
1,6-enynes
have
been
established,
simple
reductive
remains
underdeveloped.
In
this
study,
the
enantioselective
alkynyl-tethered
cyclohexadienones
(1,6-enynes)
has
developed
via
a
chiral
pincer
rhodium
catalyst,
affording
International Journal of Molecular Sciences,
Год журнала:
2024,
Номер
25(19), С. 10344 - 10344
Опубликована: Сен. 26, 2024
Chiral
pincer
complexes,
characterized
by
their
rigid
tridentate
coordination
framework,
have
emerged
as
powerful
catalysts
in
asymmetric
synthesis.
This
review
provides
a
comprehensive
overview
of
recent
advancements
the
development
chiral
pincer-type
ligands
and
corresponding
transition
metal
complexes.
We
highlight
latest
progress
application
across
range
catalytic
reactions,
including
(transfer)
hydrogenation
polar
non-polar
bonds,
hydrophosphination,
alkynylation,
Friedel-Crafts
enantioselective
reductive
cyclization
alkynyl-tethered
cyclohexadienones,
hydrosilylation,
well
Aza–Morita–Baylis–Hillman
reactions.
The
structural
rigidity
tunability
complexes
enable
precise
control
over
stereoselectivity,
resulting
high
enantioselectivity
efficiency
complex
molecular
transformations.
As
field
advances,
innovations
ligand
design
exploration
new
centers
are
expected
to
expand
scope
utility
these
catalysts,
bearing
significant
implications
for
synthesis
enantioenriched
compounds
pharmaceuticals,
materials
science,
beyond.
We
report
a
radical
cyano-cyclization
of
1,6-enynes
with
isonitriles
via
photochemically
driven
nickel
catalysis,
forging
alkenyl
nitrile-tethered
γ-lactams
under
mild
conditions.
This
reaction
leverages
the
photoexcitation
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Янв. 1, 2024
A
Pd-catalyzed,
regio-
and
diastereoselective
cascade
reaction
of
biphenyl
amines
with
1,6-enynes
via
non-rollover
cyclometallation
has
been
described
for
the
synthesis
benzoisoindolinone
derivatives.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 12, 2024
Due
to
their
important
potential
medicinal
value,
chemists
are
pursuing
mild
and
efficient
methods
synthesize
structurally
diverse
quinazolinone
derivatives.
In
this
paper,
a
series
of
isocyano-tethered
Chemical Science,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 12, 2024
The
development
of
transition
metal-catalyzed
[(2+2)+1]
and
[(2+2)+2]
carbocyclization
reactions
1,6-enynes
bearing
1,1-disubstituted
olefins
is
discussed,
highlighting
both
the
challenges
opportunities
for
expanding
this
powerful
transformation.
