Journal of the American Chemical Society,
Год журнала:
2019,
Номер
141(50), С. 19917 - 19934
Опубликована: Дек. 6, 2019
Catalytic
enantioselective
methods
are
introduced
that
allow
access
to
a
variety
of
allyl
boronates
and
silanes
contain
difluoroalkene
unit;
the
resulting
products
may
be
used
for
preparation
organofluorine
compounds
in
high
enantiomeric
purity.
Furthermore,
number
key
mechanistic
aspects
transformations
have
been
investigated
analyzed.
Thus,
first,
an
NHC–Cu-catalyzed
method
boryl
substitution
with
F3C-substituted
alkenes
is
introduced.
These
processes,
unlike
previously
reported
strategies,
applicable
alkyl
as
well
aryl
substituted
substrates,
afford
bearing
moiety
(up
98%
yield
95:5
er).
Second,
corresponding
silyl
substitutions,
first
cases
their
kind,
presented
94%
97:3
Third,
experimental
computational
(DFT)
investigations
described
shed
light
on
catalytic
processes.
Evidence
(X-ray
structures
Cu–alkyl
intermediates
kinetic
studies)
put
forth
illustrating
initial
Cu–boryl
Cu–silyl
addition
significantly
faster
than
ensuing
Cu–F
elimination,
latter
step
can
facilitated
by
either
mild
Lewis
acid
(e.g.,
Li
or
Na
cation)
nucleophilic
promoter
alkoxide).
findings
together
DFT
studies
demonstrate
β-elimination
probably
proceeds
anti-stereochemistry.
Representative
ways
through
which
new
understanding
rationalize
disclosed
findings,
improve
transformation,
develop
diastereo-
provided.
For
example,
explanation
provided
regarding
why
bisphosphine–Cu
complexes
do
not
efficiently
promote
substitutions
aryl-substituted
but
facile,
how
size
ligand
impact
regioselectivity
efficiency.
Angewandte Chemie International Edition,
Год журнала:
2017,
Номер
56(43), С. 13314 - 13318
Опубликована: Авг. 29, 2017
A
method
for
the
copper-catalyzed
borylacylation
of
activated
alkenes
is
presented.
The
reaction
involves
borylcupration
alkene,
followed
by
capture
generated
alkyl-copper
intermediate
with
an
acid
chloride.
reactions
operated
low
catalyst
loading
and
generally
occurre
within
15
min
at
room
temperature
a
range
alkenes.
In
case
vinyl
arenes,
enantioselective
was
possible.
Angewandte Chemie International Edition,
Год журнала:
2019,
Номер
58(14), С. 4612 - 4616
Опубликована: Фев. 11, 2019
Abstract
An
unprecedented
arylboration
of
unactivated
terminal
alkenes,
featuring
1,
n
‐regioselectivity,
has
been
achieved
by
nickel
catalysis.
The
nitrogen‐based
ligand
plays
an
essential
role
in
the
success
this
three‐component
reaction.
This
transformation
displays
good
regioselectivity
and
excellent
functional‐group
tolerance.
In
addition,
incorporation
a
boron
group
into
products
provides
substantial
opportunities
for
further
transformations.
Also
demonstrated
is
that
can
be
readily
transformed
pharmaceutically
relevant
molecules.
Unexpectedly,
preliminary
mechanistic
studies
indicate
although
metal
migration
favors
α‐position
boron,
selective
decisive
bond
formation
favored
at
benzylic
position.
Angewandte Chemie International Edition,
Год журнала:
2020,
Номер
60(12), С. 6545 - 6552
Опубликована: Дек. 4, 2020
Abstract
Both
syn
‐
and
anti
‐β‐amino
alcohols
are
common
structural
motifs
in
natural
products,
drug
molecules,
chiral
ligands
catalysts.
However,
the
currently
available
methods
for
synthesizing
these
limited
to
generate
only
one
diastereoisomer.
Therefore,
development
of
a
unified
method
stereoselective
access
complementary
diastereomers
would
be
highly
desirable.
Herein,
we
report
dual‐metal‐catalyzed
diastereodivergent
coupling
alkoxyallenes
with
aldimine
esters.
By
carefully
selecting
two
metals
appropriate
ligands,
could
synthesize
both
alcohol
high
enantioselectivity
diastereoselectivity
from
same
set
starting
materials.
Furthermore,
stereodivergent
syntheses
all
four
stereoisomers
β‐amino
achieved.
We
demonstrated
synthetic
utility
this
by
concisely
mycestericins
F
G.
Journal of the American Chemical Society,
Год журнала:
2019,
Номер
141(50), С. 19917 - 19934
Опубликована: Дек. 6, 2019
Catalytic
enantioselective
methods
are
introduced
that
allow
access
to
a
variety
of
allyl
boronates
and
silanes
contain
difluoroalkene
unit;
the
resulting
products
may
be
used
for
preparation
organofluorine
compounds
in
high
enantiomeric
purity.
Furthermore,
number
key
mechanistic
aspects
transformations
have
been
investigated
analyzed.
Thus,
first,
an
NHC–Cu-catalyzed
method
boryl
substitution
with
F3C-substituted
alkenes
is
introduced.
These
processes,
unlike
previously
reported
strategies,
applicable
alkyl
as
well
aryl
substituted
substrates,
afford
bearing
moiety
(up
98%
yield
95:5
er).
Second,
corresponding
silyl
substitutions,
first
cases
their
kind,
presented
94%
97:3
Third,
experimental
computational
(DFT)
investigations
described
shed
light
on
catalytic
processes.
Evidence
(X-ray
structures
Cu–alkyl
intermediates
kinetic
studies)
put
forth
illustrating
initial
Cu–boryl
Cu–silyl
addition
significantly
faster
than
ensuing
Cu–F
elimination,
latter
step
can
facilitated
by
either
mild
Lewis
acid
(e.g.,
Li
or
Na
cation)
nucleophilic
promoter
alkoxide).
findings
together
DFT
studies
demonstrate
β-elimination
probably
proceeds
anti-stereochemistry.
Representative
ways
through
which
new
understanding
rationalize
disclosed
findings,
improve
transformation,
develop
diastereo-
provided.
For
example,
explanation
provided
regarding
why
bisphosphine–Cu
complexes
do
not
efficiently
promote
substitutions
aryl-substituted
but
facile,
how
size
ligand
impact
regioselectivity
efficiency.