Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(28), P. 19261 - 19270
Published: July 1, 2024
Enantioselective
construction
of
all-carbon
quaternary
stereocenters
has
attracted
much
attention
over
the
past
few
decades.
A
variety
catalytic
asymmetric
methods
have
been
disclosed
based
on
use
presynthesized
complex
reagents
that
impart
congested
steric
hindrance
to
reaction
center,
which
generally
produce
chiral
molecules
through
forming
one
C-C
bond.
The
readily
available
could
build
two
bonds
same
carbonic
center
with
concomitant
assembly
remains
challenging.
Herein,
we
disclose
a
alkyne
multifunctionalization
using
gold
and
spiro
phosphoric
acid
(SPA)
for
synergistic
catalysis.
In
this
method,
accessible
internal
alkynes
served
as
key
carbene
precursors,
followed
by
Accounts of Chemical Research,
Journal Year:
2020,
Volume and Issue:
53(9), P. 2003 - 2019
Published: Sept. 1, 2020
ConspectusYnamides
are
electron-rich
heteroatom-substituted
alkynes
with
a
C-C
triple
bond
directly
attached
to
the
amide
group.
Importantly,
this
group
is
able
impose
an
electronic
bias,
thus
resulting
in
highly
regioselective
attack
of
polarized
alkyne
by
large
variety
nucleophiles.
Over
past
two
decades,
catalytic
reactions
ynamides
have
experienced
dramatic
developments,
especially
those
catalyzed
transition
metals.
As
result,
been
widely
applied
rapid
and
efficient
assembly
versatile
structurally
complex
N-containing
molecules,
atom-economic
stereoselective
way.On
basis
newly
developed
ynamide
preparations
new
transformations,
we
first
oxidation-initiated
tandem
such
as
zinc-catalyzed
oxidation/C-H
functionalization
copper-catalyzed
oxidation/carbene
metathesis,
leading
divergent
synthesis
isoquinolones,
β-carbolines,
pyrrolo[3,4-c]quinolin-1-ones.
protocol
represents
non-noble-metal-catalyzed
intermolecular
oxidation
N-oxide
type
oxidants,
related
overoxidation
could
be
dramatically
inhibited
non-noble-metal
catalysis.
Then,
achieved
gold-catalyzed
amination-initiated
via
α-imino
gold
carbenes
for
construction
various
2-aminoindoles,
3-amino-β-carbolines,
2-aminopyrroles,
where
types
nitrene
transfer
reagents
(benzyl
azides
isoxazoles)
were
discovered.
In
particular,
use
isoxazoles
generation
metal
has
also
elegantly
exploited
Hashmi,
Liu,
many
other
groups,
providing
ready
access
wide
range
functionalized
N-heterocycles.
Moreover,
revealed
that
donor/donor
copper
generated
diyne
cyclization
under
mild
conditions.
These
novel
undergo
asymmetric
C-H
insertion,
cyclopropanation,
formal
[3
+
2]
cycloaddition
produce
diverse
chiral
polycyclic
pyrroles
good
excellent
enantioselectivities.
Thus,
strategy
may
open
avenues
reaction
ynamides,
which
remain
largely
unexplored
deserve
more
attention.
Meanwhile,
accomplished
practical
medium-sized
lactams
yttrium-catalyzed
cascade
allyl
alcohol-tethered
combination
radical
chemistry
based
on
visible-light
photoredox
catalysis
useful
2-benzhydrylindoles
3-benzhydrylisoquinolines.In
Account,
describe
panoramic
picture
our
recent
contributions
since
2015
development
application
organic
metal-catalyzed
focusing
tetrafunctionalization
ynamides.
studies
provide
not
only
attractive
methods
valuable
N-heterocycles
but
some
insights
into
exploration
carbene
chemistry.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(20)
Published: March 5, 2022
In
recent
years,
asymmetric
catalysis
of
ynamides
has
attracted
much
attention,
but
these
reactions
mostly
constructed
central
chirality,
except
for
a
few
examples
on
the
synthesis
axially
chiral
compounds
which
exclusively
relied
noble-metal
catalysis.
Herein,
facile
access
to
N-heterocycles
enabled
by
Brønsted
acid-catalyzed
5-endo-dig
cyclization
is
disclosed,
represents
first
metal-free
protocol
construction
from
ynamides.
This
method
allows
practical
and
atom-economical
valuable
N-arylindoles
in
excellent
yields
with
generally
enantioselectivities.
Moreover,
organocatalysts
ligands
based
such
N-arylindole
skeletons
are
demonstrated
be
applicable
ACS Catalysis,
Journal Year:
2020,
Volume and Issue:
10(23), P. 13978 - 13992
Published: Nov. 17, 2020
Ynamides
consisting
of
an
electron-withdrawing
group
on
the
nitrogen
atom
have
proven
to
be
powerful
and
versatile
building
blocks
that
are
involved
in
a
variety
useful
chemical
transformations.
Nonetheless,
their
utilization
asymmetric
catalysis
is
still
its
infancy
has
only
recently
attracted
attention
synthetic
organic
community.
The
focus
this
review
present
overview
exciting
results
achieved
thus
far
field
catalytic
reactions
ynamides
with
emphasis
advantages,
limitations,
mechanisms,
applications
associated
current
approaches.
In
addition,
personal
outlook
challenges
limitations
need
overcome
area
also
given
at
end.
Angewandte Chemie International Edition,
Journal Year:
2020,
Volume and Issue:
59(41), P. 17984 - 17990
Published: July 4, 2020
Here
an
efficient
copper-catalyzed
cascade
cyclization
of
azide-ynamides
via
α-imino
copper
carbene
intermediates
is
reported,
representing
the
first
generation
carbenes
from
alkynes.
This
protocol
enables
practical
and
divergent
synthesis
array
polycyclic
N-heterocycles
in
generally
good
to
excellent
yields
with
broad
substrate
scope
diastereoselectivities.
Moreover,
asymmetric
azide-ynamide
has
been
achieved
high
enantioselectivities
(up
98:2
e.r.)
by
employing
BOX-Cu
complexes
as
chiral
catalysts.
Thus,
this
constitutes
example
azide-alkyne
cyclization.
The
proposed
mechanistic
rationale
for
further
supported
theoretical
calculations.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(52), P. 27164 - 27170
Published: Oct. 21, 2021
Described
herein
is
a
novel
Brønsted
acid
catalyzed
intramolecular
hydroalkoxylation/Claisen
rearrangement,
allowing
the
practical
and
atom-economic
synthesis
of
range
valuable
spirolactams
from
readily
available
ynamides
in
generally
good
to
excellent
yields
with
diastereoselectivities
broad
substrate
scope.
Importantly,
an
unexpected
dearomatization
nonactivated
arenes
heteroaromatic
compounds
involved
this
tandem
sequence.
Moreover,
asymmetric
version
cyclization
was
also
achieved
by
efficient
kinetic
resolution
chiral
phosphoric
catalysis.
In
addition,
[3,3]-rearrangement
shown
be
kinetically
preferred
over
related
[1,3]-rearrangement
theoretical
calculations.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
61(7)
Published: Dec. 14, 2021
Here,
we
report
a
copper-catalyzed
asymmetric
cascade
cyclization/[1,2]-Stevens-type
rearrangement
via
non-diazo
approach,
leading
to
the
practical
and
atom-economic
assembly
of
various
valuable
chiral
chromeno[3,4-c]pyrroles
bearing
quaternary
carbon
stereocenter
in
generally
moderate
good
yields
with
wide
substrate
scope
excellent
enantioselectivities
(up
99
%
ee).
Importantly,
this
protocol
not
only
represents
first
example
catalytic
[1,2]-Stevens-type
based
on
alkynes
but
also
constitutes
formal
carbene
insertion
into
Si-O
bond.