En Route to Diastereopure Polycyclic γ‐Lactones by Iridium‐Catalyzed Hydride Transfer†
Chinese Journal of Chemistry,
Journal Year:
2024,
Volume and Issue:
42(23), P. 3047 - 3055
Published: July 30, 2024
Comprehensive
Summary
The
reductive
lactonization
strategy
provides
an
efficient
access
to
diastereoenriched
polycyclic
γ‐lactones.
However,
it
is
still
a
formidable
challenge
develop
and
versatile
protocol
with
excellent
levels
of
diastereocontrol.
Herein,
we
provide
highly
diastereoselective
route
diastereopure
bi‐
γ‐lactones,
by
means
iridium‐catalyzed
hydride
transfer
strategy.
This
method
features
high
diastereocontrol,
broad
substrate
scope,
catalyst
efficiency
(
S
/
C
=
up
5000).
Mechanistic
studies
suggest
that
the
iridium
formation
might
be
rate‐determining
step,
step
diastereo‐determining
step.
large
steric
hindrance
species
intramolecular
hydrogen
bonding
are
critically
key
diastereocontrol
process.
From
perspectives
configurational
analysis
Duniz
angles
attack,
nature
well
rationalized.
A
more
general
empirical
rule
based
on
facial
selectivity
for
explaining
predicting
stereochemistry
also
proposed.
Language: Английский
Iridium-Catalyzed Highly Selective 1,4-Reduction of α,β-Unsaturated Carbonyl Compounds
Molecules,
Journal Year:
2024,
Volume and Issue:
29(24), P. 5912 - 5912
Published: Dec. 14, 2024
In
this
study,
an
iridium-catalyzed
selective
1,4-reduction
of
α,β-unsaturated
carbonyl
compounds
is
realized,
with
water
as
a
solvent
and
formic
acid
hydride
donor.
The
new
efficient
iridium
catalyst
features
2-(4,5-dihydroimidazol-2-yl)quinoline
ligand.
chemoselectivity
efficiency
are
highly
dependent
on
the
electronic
steric
properties
substrates.
For
amides,
acids,
esters,
only
electron-deficient
C=C
bonds
reduced
(1,4-reduction),
other
functional
groups
left
intact.
S/C
ratio
initial
TOF
reach
7000
18,480
h−1,
respectively.
A
gram-scale
also
performed.
Deuterium
labeling
shows
that
β-hydrogens
products
originate
from
formyl
hydrogen
in
acid.
application
for
modification
structures
some
medications
demonstrated.
Language: Английский
Phthalimidine Synthesis via Iridium-Catalyzed Reductive Lactamization
The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 24, 2024
Herein,
we
report
a
sustainable
and
efficient
method
for
the
synthesis
of
structurally
diverse
phthalimidines
from
2-formylbenzoic
acid
primary
amines
using
an
iridium-catalyzed
reductive
lactamization
strategy.
The
advantages
this
method,
such
as
use
water–ethanol
solvent,
broad
substrate
scope,
high
catalyst
efficiency
(S/C
up
to
10000),
good
scalability,
easy
purification,
enable
it
be
practical
approach
phthalimidines.
It
is
suggested
that
iridium
hydride
formation
involved
in
rate-limiting
step.
Synthetic
applications
late-stage
functionalization
medicinally
relevant
molecules
are
also
demonstrated.
Language: Английский