Abstract
A
Rh‐catalyzed
asymmetric
hydroboration
of
dialkyl
ketone‐derived
silyl
enol
ethers
with
HBpin
has
been
developed
using
a
commercially
available
catalyst
and
ligand
([RhCl
(cod)]
2
MeO‐BIBOP).
variety
undergo
this
transformation,
providing
the
corresponding
products
high
enantioselectivity
(up
to
97
:
3
%
er).
In
addition,
utility
protocol
is
demonstrated
by
versatile
transformation
chiral
borylether
range
valuable
derivatives.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(23), С. 16194 - 16202
Опубликована: Июнь 4, 2024
Although
progress
has
been
made
in
enantioselective
hydroboration
of
di-
and
trisubstituted
alkenes
over
the
past
decades,
tetrasubstituted
with
high
diastereo-
enantioselectivities
continues
as
an
unmet
challenge
since
1950s
due
to
its
extremely
low
reactivity
difficulties
simultaneously
control
regio-
stereoselectivity
a
alkene.
Here,
we
report
highly
regio-,
diastereo-,
catalytic
diverse
acyclic
alkenes.
The
delicate
interplay
electron-rich
rhodium
complex
coordination-assistance
forms
adaptive
catalyst
that
effectively
overcomes
controls
stereoselectivity.
generality
system
is
exemplified
by
efficacy
across
various
steric
electronic
properties.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 25, 2025
Arylidenecyclobutanes
are
readily
accessible
and
versatile
reagents
in
synthetic
chemistry
due
to
the
multifaceted
reactivity
exhibited
by
their
alkene
strained
cyclobutane
moieties.
However,
metal-catalyzed
enantioselective
functionalization
of
arylidenecyclobutanes,
particularly
controllable
ring-retaining
ring-opening
reactions,
is
rarely
explored.
Considering
utility
enantioenriched
organoboronate
compounds,
herein
we
report
ligand-controlled
copper-catalyzed
hydroboration
dihydroboration
reactions
arylidenecyclobutanes
that
afford
chiral
α-cyclobutyl
benzylboronate
1,5-diboronate
compounds
with
high
enantioselectivity
when
(S)-DTBM-Segphos
(S,S)-Ph-BPE
employed,
respectively.
Mechanistic
studies
reveal
process
via
β-C
elimination
significantly
slower
than
arylidenecyclopropanes
presence
CuOAc
(S,S)-Ph-BPE.
The
these
two
protocols
further
demonstrated
through
conducting
various
stereospecific
site-selective
transformations
organoboron
products,
including
concise
synthesis
bioactive
molecules.
Chinese Journal of Organic Chemistry,
Год журнала:
2022,
Номер
42(10), С. 3167 - 3167
Опубликована: Янв. 1, 2022
Transition
metal
catalyzed
asymmetric
hydroboration
of
alkenes
is
one
the
most
powerful
methods
to
prepare
chiral
organoboronates,
which
has
attracted
extensive
attention
chemists
due
its
simple
raw
materials,
high
atomic
economy,
diverse
structure
borated
products,
etc.The
transition
enantioselective
internal
including
strained
alkene,
β-substituted
styrenes
and
bearing
a
coordinating
group
summarized.
ACS Catalysis,
Год журнала:
2023,
Номер
14(1), С. 418 - 425
Опубликована: Дек. 20, 2023
Miyaura
borylation
is
widely
recognized
as
one
of
the
most
reliable
methods
for
constructing
an
organoboron
compound.
Reported
herein
Pd(0)-catalyzed
asymmetric
three-component
Heck–Miyaura
with
interception
internal
olefin,
aryldiazonium
salt,
and
diboron
reagent.
This
Heck-triggered
protocol
proceeds
in
a
highly
chemoselective,
diastereoselective,
enantioselective
manner,
thus
allowing
expedient
construction
1,2-diaryl
substituted
β-aminoboronate
esters
derivatives
vicinal
stereogenic
centers.
The
versatility
resulting
benzylic
boronic
allows
their
further
transformation
to
more-intricate
chiral
amines.
Abstract
Catalytic
asymmetric
hydroboration
of
fluoroalkyl‐substituted
alkenes
is
a
straightforward
approach
to
access
chiral
small
molecules
possessing
both
fluorine
and
boron
atoms.
However,
enantioselective
without
elimination
has
been
long‐standing
challenge
in
this
field.
Herein,
copper‐catalyzed
difluoroalkyl‐substituted
internal
with
high
levels
regio‐
enantioselectivities
reported.
The
native
carbonyl
directing
group,
copper
hydride
system,
bisphosphine
ligand
play
crucial
roles
suppressing
the
undesired
fluoride
elimination.
This
atom‐economic
protocol
provides
practical
synthetic
platform
obtain
wide
scope
enantioenriched
secondary
boronates
bearing
difluoromethylene
moieties
under
mild
conditions.
Synthetic
applications
including
functionalization
biorelevant
molecules,
versatile
functional
group
interconversions,
preparation
difluoroalkylated
Terfenadine
derivative
are
also
demonstrated.
ACS Catalysis,
Год журнала:
2024,
Номер
14(11), С. 8949 - 8957
Опубликована: Май 28, 2024
The
cycloaddition
and
annulation
reactions
of
Achmatowicz
rearrangement
products
(ARPs)
are
critically
important
to
the
construction
molecular
complexity
total
synthesis
natural
products.
However,
this
field
is
still
blemished
by
shortage
enantioselective
(3+2)
ARPs.
Herein,
we
report
highly
enantio-,
diastereo-,
regioselective
annulations
ARPs
with
nucleophilic
α-thioacyl
Rh(I)-carbenes
under
Rh(I)/(R)-BINAP
catalysis,
producing
bicyclic
dihydrothiophenes
multiple
functionalities,
three
continuous
chiral
centers,
five
prochiral
centers
in
up
97%
yields
99:1
er.
Mechanistically,
migratory
insertion
following
anticoordination
suggested
determine
enantio-
regioselectivities
accounts
for
character
Rh(I)-carbenes.
DFT
calculations
revealed
that
enantioinduction
originates
from
steric
discrimination
(R)-
(S)-ARPs
ligand.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(12), С. 9056 - 9062
Опубликована: Июнь 10, 2024
A
palladium(II)-catalyzed
Markovnikov
hydroboration
of
aryl
alkenes
with
readily
available
bis(pinacolato)diboron
(B2pin2)
is
reported.
The
reaction
proceeded
low
catalyst
loading
(0.5
mol
%)
in
the
absence
N-
or
P-containing
ligands,
affording
products
up
to
90%
yield.
Trifluoracetic
acid
serves
as
hydrogen
source,
enabling
synthesis
benzylic
boronic
esters
under
mild
ambient
conditions.
Green Chemistry,
Год журнала:
2023,
Номер
25(9), С. 3715 - 3722
Опубликована: Янв. 1, 2023
ILs
organocatalyzed
regioselective
hydroboration
of
alkenes
with
HBpin
provides
anti-Markovnikov
adducts
high
yields
and
selectivity.
The
system
allows
catalyst
recycling
up
to
30
runs.
Transformations
alkylboronic
esters
are
also
included.
