Chemistry - A European Journal,
Journal Year:
2022,
Volume and Issue:
28(46)
Published: June 2, 2022
Abstract
The
aza‐
ortho
‐quinone
methide
(aza‐
o
‐QM)
chemistry
has
overwhelmingly
progressed
in
the
past
few
decades.
This
review
aims
to
integrate
various
transition
metal‐catalyzed
and
organocatalytic
strategies
taming
aza
‐o‐
QM
intermediates,
including
‐vinylidene
quinone
‐VQM),
‐alkynyl
‐AQM),
para
p
‐QM),
indole‐based
‐QM
analog.
These
transient
species
are
often
utilized
for
direct
enantioselective
synthesis
of
complex
(hetero)polycyclic
or
fused‐ring
molecular
scaffolds
such
as
tetrahydroquinoline
indoline,
among
others,
which
abundant
many
natural
products,
bioactive
compounds,
pharmaceuticals.
European Journal of Organic Chemistry,
Journal Year:
2020,
Volume and Issue:
2020(18), P. 2650 - 2692
Published: Feb. 28, 2020
para
‐Quinone
methides
(
p
‐QMs)
are
naturally
occurring
molecules
that
have
been
finding
increasing
synthetic
applications
in
the
last
few
years.
The
presence
of
two
electronically
different
exocyclic
conjugate
substituents
their
structure,
carbonyl
and
methylidene,
leads
to
a
pronounced
reactivity
owing
polarization
molecule.
In
this
sense,
those
prone
undergo
attack
nucleophiles
terminal
carbon
double
bond,
behaving
as
vinylogous
electrophiles
generating
1,6‐addition
products.
context,
years
development
catalytic
approaches
for
1,6‐nucleophilic
addition
reactions
involving
‐QMs
has
attracted
considerable
attention.
Considering
extensive
such
found
decades
reactions,
review
we
comprehensively
discuss
historical
field,
starting
with
early
on
natural
product
synthesis,
going
through
seminal
non‐stereoselective
processes
progressing
cutting‐edge
asymmetric‐catalyzed
approaches.
Angewandte Chemie International Edition,
Journal Year:
2020,
Volume and Issue:
59(39), P. 17049 - 17054
Published: June 18, 2020
An
organocatalytic
enantioconvergent
synthesis
of
chiral
tetrasubstituted
allenes
is
disclosed.
With
suitable
phosphoric
acid
catalysts,
a
range
racemic
indole-substituted
propargylic
alcohols
reacted
with
nucleophiles
to
provide
efficient
access
series
enantioenriched
high
enantioselectivities.
Control
experiments
suggested
mechanism
involving
remotely
controlled
asymmetric
1,8-addition
the
in
situ
generated
indole
imine
methide
via
bifunctional
transition
state.
Advanced Synthesis & Catalysis,
Journal Year:
2022,
Volume and Issue:
364(7), P. 1212 - 1222
Published: March 9, 2022
Abstract
Axially
chiral
allenes
occur
on
a
wide
range
of
natural
products
and
synthetic
molecules
with
significant
biological
activity.
Furthermore,
they
are
versatile
building
blocks
in
organic
synthesis
because
their
inherent
chemical
properties.
Accordingly,
catalytic
enantioselective
axially
has
been
paid
much
attention.
Benefited
from
the
development
asymmetric
organocatalysis,
many
simple
efficient
methods
terms
different
systems
as
well
reaction
partners
have
developed.
This
review
will
focus
recent
progress
field
organocatalytic
(2000–2022),
which
is
organized
according
to
types
catalyst
system
used.
magnified
image
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(31)
Published: June 1, 2023
The
skeletons
of
chiral
tetrasubstituted
allenes
bearing
a
vicinal
all-carbon
quaternary
stereocenter
are
importance
but
still
challenging
to
synthesize.
Herein,
we
report
enantio-
and
diastereoselective
γ-additions
1-alkynyl
ketimines
with
dual-copper-catalysis
under
mild
conditions,
affording
α-amino
allenoates
in
high
yields
(up
99
%
yield)
excellent
enantioselectivities
ee)
diastereoselectivities
>20
:
1
dr).
Importantly,
the
stereodivergent
synthesis
products
was
realized
by
asymmetric
γ-addition
reaction
Grignard
reagent
promoted
epimerization.
Moreover,
dual-copper-catalyzed
reactions
were
smoothly
applied
gram-scale
adopted
introduce
allenyl
moieties
into
bioactive
molecules.
Mechanistic
experiments
density
functional
theory
(DFT)
calculations
demonstrated
that
catalyzed
double
copper
catalysts.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(23), P. 12802 - 12811
Published: June 5, 2023
Quinone
methides
are
well-established
intermediates
in
asymmetric
synthesis.
In
contrast,
their
extended
analogues
with
the
carbonyl
and
methide
units
distributed
across
two
different
rings
have
not
been
exploited
Herein,
we
achieved
first
process
involving
such
intermediates.
Specifically,
use
of
suitable
chiral
phosphoric
acids
enabled
situ
generation
2-naphthoquinone
8-methides
corresponding
aza
counterparts
for
mild
one-pot
nucleophilic
addition.
These
processes
provided
rapid
access
to
a
wide
range
previously
less
accessible
remotely
naphthols
naphthylamines
both
high
efficiency
excellent
enantioselectivity.
Control
experiment
DFT
calculations
important
insights
into
reaction
mechanism,
which
likely
involves
acid
molecules
enantiodetermining
transition
states.
This
work
serves
as
proof
concept
exploitation
new
types
quinone
versatile
synthesis,
thus
providing
platform
efficient
construction
remote
benzylic
stereogenic
centers
aromatic
compounds.
Chemical Society Reviews,
Journal Year:
2024,
Volume and Issue:
53(22), P. 11165 - 11206
Published: Jan. 1, 2024
This
review
explores
the
fascinating
world
of
molecules
featuring
multiple
stereogenic
elements,
unraveling
different
strategies
designed
over
years
for
their
enantioselective
synthesis.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(11), P. 7419 - 7430
Published: March 6, 2024
The
first
earth-abundant
transition
metal
Ni-catalyzed
highly
regio-
and
enantioselective
semihydrogenation
of
racemic
tetrasubstituted
allenes
via
a
kinetic
resolution
process
as
challenging
task
was
well
established.
This
protocol
furnishes
expedient
access
to
diversity
structurally
important
enantioenriched
chiral
allylic
molecules
with
high
regio-,
enantio-,
Z/E-selectivity.
Remarkably,
this
proceeded
one
carbon–carbon
double
bond
allenes,
which
regioselective
complementary
the
Rh-catalyzed
asymmetric
version.
Deuterium
labeling
experiments
density
functional
theory
(DFT)
calculations
were
carried
out
reveal
reasonable
reaction
mechanism
explain
regio-/stereoselectivity.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(22)
Published: March 23, 2024
Abstract
Despite
the
significance
of
chiral
allene
skeletons
in
catalysis,
organic
synthesis
and
medicinal
chemistry
et
al.,
there
is
a
scarcity
reports
on
axially
allenyl
phosphorus
compounds.
Here,
we
disclosed
an
efficient
straightforward
cascade
reaction
between
ethynyl
ketones
phosphine
oxides,
resulting
broad
array
trisubstituted
allenes
incorporating
moiety
high
yields
with
excellent
stereoselectivities
facilitated
by
peptide‐mimic
phosphonium
salt
(PPS)
Additionally,
comprehensive
series
mechanistic
experiments
have
been
conducted
to
elucidate
that
this
proceeds
via
asymmetric
Pudovik
addition
followed
subsequent
phospha
‐Brook
rearrangement
occurs
concomitantly
kinetic
resolution,
representing
stereospecific
protonation
process
facilitating
central‐to‐axial
chirality
transfer
manner.
We
anticipate
our
research
will
pave
way
for
promising
exploration
novel
stereo‐induction
pattern
addition/
reaction.
Chemical Science,
Journal Year:
2019,
Volume and Issue:
11(3), P. 671 - 676
Published: Dec. 6, 2019
The
first
chiral
phosphoric
acid
catalyzed
asymmetric
multiple
dearomatizations
of
phenols
for
the
synthesis
bridged
polycyclic
compounds
are
reported.