Angewandte Chemie,
Год журнала:
2022,
Номер
134(41)
Опубликована: Авг. 23, 2022
Abstract
Reported
herein
is
the
efficient
synthesis
of
tetra‐
and
tri‐substituted
(
Z
)‐fluoro‐
)‐chloro‐borylalkenes
by
Boron–Wittig
reaction
ketones
aldehydes
with
bench‐top
stable
halo‐diborylmethanes.
The
substrate
scope
broad
proceeds
from
a
diverse
range
including
biologically
relevant
molecules
fluoro‐
or
chloro‐diborylmethanes,
providing
in
good
yields
high
stereoselectivity.
utilities
obtained
are
highlighted
further
modifications
to
afford
fluoroalkene
derivatives
all‐carbon
substituted
alkene.
Angewandte Chemie International Edition,
Год журнала:
2019,
Номер
59(5), С. 2039 - 2043
Опубликована: Ноя. 6, 2019
Abstract
The
stereodivergent
iridium‐catalyzed
allylic
alkylation
and
fluorination
of
acyclic
ketones
is
described.
α‐Pyridyl‐α‐fluoroketones
with
vicinal
tertiary
quaternary
stereocenters
were
obtained
in
moderate
to
excellent
yields
stereoselectivities.
Distinct
from
known
synthesis,
for
which
two
different
chiral
catalysts
are
required
general,
herein
we
report
a
sequence‐dependent
synthesis.
With
only
single
Ir
catalyst,
all
four
possible
stereoisomers
the
products
prepared
same
starting
materials
by
simply
adjusting
sequence
asymmetric
varying
absolute
configuration
catalyst.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(37)
Опубликована: Июль 18, 2022
Abstract
The
development
of
new
approaches
to
installing
diverse
carbon
fragments
a
nitrogen
atom
has
attracted
considerable
attention
in
chemical
science.
While
numerous
strategies
have
been
devised
forge
C(sp
3
)−N
bonds,
one
conceptually
powerful
and
straightforward
approach
is
insert
transformable
sp
‐carbon
unit
onto
for
modular
diversification.
Here
we
describe
the
successful
synthesis
halo‐diborylmethanes
their
applications
preparation
nitrogen‐substituted
diborylmethanes
through
homologative
coupling
with
variety
nucleophiles
including
biologically
relevant
molecules.
This
process
exhibits
remarkably
broad
substrate
scope,
usefulness
obtained
compounds
demonstrated
by
diversification
diborylmethyl
group
access
various
nitrogen‐containing
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(14)
Опубликована: Фев. 1, 2023
This
report
describes
the
unprecedented
electrooxidation
of
a
solvent
(e.g.,
DMF)-ligated
B2
cat2
complex,
whereby
solvent-stabilized
boryl
radical
is
formed
via
quasi-homolytic
cleavage
B-B
bond
in
DMF-ligated
cation.
Cyclic
voltammetry
and
density
functional
theory
provide
evidence
to
support
this
novel
activation
strategy.
Furthermore,
strategy
for
electrochemical
gem-diborylation
gem-bromides
paired
electrolysis
developed
first
time,
affording
range
versatile
gem-diborylalkanes,
which
are
widely
used
synthetic
society.
Notably,
reaction
approach
scalable,
transition-metal-free,
requires
no
external
activator.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(30)
Опубликована: Май 24, 2022
A
cobalt-catalyzed
asymmetric
sequential
hydroboration/isomerization/hydroboration
of
2-aryl
vinylcyclopropanes
was
for
the
first
time
reported
preparation
valuable
chiral
1,5-bis(boronates)
in
good
yields
with
excellent
enantioselectivity
via
isomerization/hydroboration
a
trisubstituted
alkene
intermediate.
The
reaction
carried
out
smoothly
and
this
protocol
used
syntheses
(-)-preclamol
gram-scale.
two
primary
C(sp3)
-B
bonds
could
be
distinguished
iterative
Suzuki-Miyaura
cross-coupling
reaction,
delivering
1,2,5-triaryl
alkanes
enantioselectivity.
Based
on
experimental
computational
studies,
cobalt-hydride
species
proposed
as
active
intermediate
hydroboration,
isomerization,
second
hydroboration
reactions.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(41)
Опубликована: Авг. 23, 2022
Reported
herein
is
the
efficient
synthesis
of
tetra-
and
tri-substituted
(Z)-fluoro-
(Z)-chloro-borylalkenes
by
Boron-Wittig
reaction
ketones
aldehydes
with
bench-top
stable
halo-diborylmethanes.
The
substrate
scope
broad
proceeds
from
a
diverse
range
including
biologically
relevant
molecules
fluoro-
or
chloro-diborylmethanes,
providing
in
good
yields
high
stereoselectivity.
utilities
obtained
are
highlighted
further
modifications
to
afford
fluoroalkene
derivatives
all-carbon
substituted
alkene.
Angewandte Chemie International Edition,
Год журнала:
2019,
Номер
58(31), С. 10493 - 10499
Опубликована: Май 13, 2019
Abstract
Described
herein
is
an
asymmetric
allylic
aromatization
(AAAr)
strategy
that
employs
readily
accessible
equivalents
of
benzylic
nucleophiles
in
iridium‐catalyzed
substitution
reactions
with
the
concomitant
formation
aromatic
rings
by
aromatization.
The
optimized
reaction
conditions
involving
a
catalyst
derived
from
commercially
available
iridium
precursor
and
Carreira
ligand
are
compatible
4‐
or
5‐methyloxazoles,
5‐methylthiazoles,
5‐methylfurans,
2‐
3‐methylbenzofurans,
3‐methylbenzothiophene,
3‐methylindole,
1‐methylnaphthalene,
methylbenzene.
This
provides
straightforward
accesses
to
valuable
heterocyclic
compounds,
bearing
homobenzylic
stereogenic
center,
enantiopure
form
would
be
difficult
access
otherwise.
versatility
was
showcased
further
elaboration
products
into
useful
building
blocks
drug
analogue.
Angewandte Chemie International Edition,
Год журнала:
2020,
Номер
59(32), С. 13608 - 13612
Опубликована: Апрель 16, 2020
A
general
and
atom-economical
synthesis
of
1,1-diborylalkanes
from
alkenes
a
borane
without
the
need
for
an
additional
H2
acceptor
is
reported
first
time.
The
key
to
our
success
use
earth-abundant
zirconium-based
catalyst,
which
allows
balance
self-contradictory
reactivities
(dehydrogenative
boration
hydroboration)
be
achieved.
Our
method
avoids
using
excess
amount
another
alkene
as
acceptor,
was
required
in
other
systems.
Furthermore,
substrates
such
simple
long-chain
aliphatic
that
did
not
react
before
also
underwent
1,1-diboration
system.
Significantly,
unprecedented
internal
enabled
preparation
1,1-diborylalkanes.
Chemistry - A European Journal,
Год журнала:
2020,
Номер
26(24), С. 5360 - 5364
Опубликована: Март 6, 2020
Abstract
The
use
of
gem
‐diborylalkenes
as
radical‐reactive
groups
is
explored
for
the
first
time.
These
reactions
provide
an
efficient
and
general
method
photochemical
conversion
to
rapidly
access
1,1‐bisborylalkanes.
This
exploits
a
novel
photoredox
decarboxylative
radical
addition
afford
α‐
‐diboryl
carbon‐centered
radicals,
which
benefit
from
additional
stability
by
virtue
interaction
with
empty
p‐orbitals
on
borons.
reaction
offers
highly
modular
regioselective
approach
γ‐amino
‐diborylalkanes.
Furthermore,
EPR
spectroscopy
DFT
calculations
have
provided
insight
into
mechanism
underlying
photochemistry
bis‐metalated
respectively.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(20)
Опубликована: Март 3, 2022
Abstract
Herein,
an
Ir‐catalyzed
asymmetric
allylic
substitution
reaction
of
methyl
azaarenes
is
described.
Azaarenes
such
as
(benzo)thiazole,
oxazole,
benzoimidazole,
pyridine,
and
(iso)quinoline
are
all
tolerated.
The
corresponding
chiral
azaarene
derivatives
obtained
in
good
yields
with
high
enantioselectivity
(up
to
96
%
yield
99
ee).
utilization
the
Knochel
reagent
TMPZnBr⋅LiBr
warrants
situ
formation
benzylic
nucleophiles
without
additional
activating
reagents.
1
H
NMR
studies
suggested
a
two‐fold
function
this
reaction.
synthetic
utility
method
has
been
showcased
by
concise
enantioselective
synthesis
allosteric
protein
kinase
modulator.
Chemistry - A European Journal,
Год журнала:
2019,
Номер
25(34), С. 8013 - 8017
Опубликована: Апрель 24, 2019
Vinyl
epoxides
and
styrene
oxide
can
react
with
diborylmethide
lithium
salts
through
an
exclusive
SN
2
borylmethylation/ring
opening
in
a
regio-
diastereoselective
way,
depending
on
the
nature
of
substrate.
The
ring-opening
protocol
provides
homoallylboronates
that
be
transformed
into
challenging
diastereomeric
bishomoallylic
alicyclic
1,3-diols.
Unprecedented
3-borylated
1,2-oxaborolan-2-ol
products
were
prepared
by
2-methyl-2-vinyloxirane
followed
intramolecular
cyclization.
