IntechOpen eBooks,
Journal Year:
2021,
Volume and Issue:
unknown
Published: May 14, 2021
In
this
chapter,
the
strategies
developed
to
attain
asymmetric
reactions
with
gold
are
disclosed.
Because
of
its
preferred
linear
arrangement,
induce
asymmetry,
gold(I)
needs
fulfill
one
following
requirements:
a)
use
bulky
chiral
ligands,
that
create
a
pocket
around
active
site,
b)
coordination
bifunctional
ligands
capable
establish
secondary
interactions
substrates,
or
c)
tight
ion
pairing
counteranions.
On
other
hand,
gold(III)
profits
square-planar
mode,
which
approaches
substrates.
However,
tendency
be
reduced
leads
difficulties
for
applications
in
catalytic
transformations.
Pioneering
works
using
cyclometaled
structures,
have
found
balance
between
stability
and
activity,
showing
potential
Angewandte Chemie International Edition,
Journal Year:
2020,
Volume and Issue:
60(5), P. 2355 - 2363
Published: Oct. 22, 2020
Abstract
The
regio‐
and
enantioselective
(3+3)
cycloaddition
of
nitrones
with
2‐indolylmethanols
was
accomplished
by
the
cooperative
catalysis
hexafluoroisopropanol
(HFIP)
chiral
phosphoric
acid
(CPA).
Using
this
approach,
a
series
indole‐fused
six‐membered
heterocycles
were
synthesized
in
high
yields
(up
to
98
%),
excellent
enantioselectivities
96
%
ee
)
exclusive
regiospecificity.
This
approach
enabled
not
only
first
organocatalytic
asymmetric
but
also
C3‐nucleophilic
2‐indolylmethanols.
More
importantly,
theoretical
calculations
elucidated
role
cocatalyst
HFIP
helping
CPA
control
reactivity
enantioselectivity
reaction,
demonstrating
new
mode
catalysis.
Accounts of Chemical Research,
Journal Year:
2020,
Volume and Issue:
53(10), P. 2358 - 2371
Published: Oct. 1, 2020
ConspectusA
small-molecule
collection
with
structural
diversity
and
complexity
is
a
prerequisite
to
using
either
drug
candidates
or
chemical
probes
for
discovery
chemical–biology
investigations,
respectively.
Over
the
past
12
years,
we
have
engaged
in
developing
efficient
diversity-oriented
cascade
strategies
synthesis
of
topologically
diverse
skeletons
incorporating
biologically
relevant
motifs
such
as
O-
N-heterocycles,
fused
polycycles,
multifunctionalized
allenes.
In
particular,
highlighted
use
simple,
linear,
densely
functionalized
molecular
platforms
these
reactions.This
account
details
our
efforts
design
novel
metal-
organo-catalyzed
reactions,
which
include
2-(1-alknyl)-2-alken-1-ones
(yne–enones)
heterocyclization/cross-coupling
cascades,
heterocyclization/cycloaddition
nucleophilic
addition/cross-coupling
addition/heterocyclization
so
on.
Moreover,
this
Account
outlines
corresponding
mechanistic
insights,
computational
information,
applications
cascades
construction
various
highly
substituted
carbo-
heterocycles
well
acyclic
compounds,
e.g.,
allenes
dienes.
addition
yne–enones,
evolved
functional
groups
original
yne–enones
provide
series
yne–enone
variants,
resulted
products
complementary
reactivities.The
reactivity
profile
defined
by
presence
an
alkyne
moiety
conjugated
enone
unit
their
mutual
through-bond
connectivity.
Owing
conceptually
rapid
development
carbophilic
activation,
identified
catalytic
systems
consisting
metal
catalysts,
including
Pd,
Au,
Rh
complexes,
catalysis,
allowing
unprecedented
reactions
be
achieved
through
different-types
reaction
intermediates,
all-carbon
1,n-dipoles,
furan-based
o-quinodimethanes
(oQDMs),
allenyl-metal
species.
commonly
known
transition-metal
activity,
Lewis
acidity
complexes
crucial
accomplish
transformation.
addition,
enantioselective
gold(I)-catalyzed
variants
were
application
bisphosphines
(e.g.,
Cn-TunePhos),
monophosphines,
developed
"Ming–Phos"
chiral
ligands.
Importantly,
Ming–Phos
ligands
exhibited
excellent
performance
gold-catalyzed
mechanistically
distinct
[3
+
n]-cycloaddition
sulfinamide
possibly
responsible
interaction
substrate
control
enantioselectivity.
Subsequently,
demonstrated
that
easily
prepared
polymer-supported
ligand
could
applied
heterogeneously
asymmetric
cycloaddition
good
stereocontrol.
With
metal-free
divergent
functionalization
provides
numerous
synthetic
outlets
structure
diversification.
For
example,
are
particularly
attractive
precursors
achiral
heterocycles,
pyrazoles,
isoxazoles,
pyrroles,
pyrans,
etc.
Chemistry - An Asian Journal,
Journal Year:
2021,
Volume and Issue:
16(5), P. 364 - 377
Published: Jan. 2, 2021
Asymmetric
gold
catalysis
has
been
rapidly
developed
in
the
past
ten
years.
Breakthroughs
have
made
by
rational
design
and
meticulous
selection
of
chiral
ligands.
This
review
summarizes
newly
gold-catalyzed
enantioselective
organic
transformations
recent
progress
ligand
(since
2016),
organized
according
to
different
types
ligands,
including
bisphosphine
monophosphine
phosphite-derived
N-heterocyclic
carbene
ligands
for
asymmetric
gold(I)
as
well
heterocyclic
oxazoline
gold(III)
catalysis.
ChemPlusChem,
Journal Year:
2021,
Volume and Issue:
86(9), P. 1283 - 1296
Published: July 12, 2021
Abstract
Gold(I)
catalysts
are
ideal
for
the
activation
of
alkynes
under
very
mild
conditions.
However,
unlike
allenes
or
alkenes,
triple
bond
cannot
be
prochiral.
In
addition,
linear
coordination
displayed
by
gold(I)
complexes
places
chiral
ligand
far
away
from
substrate
resulting
in
an
inefficient
transfer
information.
This
poses
a
significant
challenge
achievement
high
enantiocontrol
gold(I)‐catalyzed
reactions
alkynes.
Although
considerable
progress
on
enantioselective
transformations
has
recently
been
achieved,
asymmetric
non‐prochiral
alkyne‐containing
small
molecules
still
represents
great
challenge.
Herein
we
summarize
recent
advances
intra‐
and
intermolecular
involving
alkynes,
discussing
new
designs
that
lie
at
basis
these
developments.
We
also
focus
mode
action
catalysts,
their
possible
limitations
towards
next‐generation
more
efficient
designs.
Finally,
square
planar
gold(III)
complexes,
which
offer
alternative
to
discussed.
New Journal of Chemistry,
Journal Year:
2021,
Volume and Issue:
45(26), P. 11420 - 11456
Published: Jan. 1, 2021
The
1,3-dipolar
cycloaddition
reaction
of
nitrone
is
one
the
most
important
methods
for
synthesis
different
sizes
heterocycles
which
have
enormous
applications
in
natural
products,
biologically
active
molecules
and
pharmaceuticals.
ACS Catalysis,
Journal Year:
2022,
Volume and Issue:
12(7), P. 4046 - 4053
Published: March 16, 2022
Gold(I)
complexes
of
a
chiral
phosphoric
acid-functionalized
phosphine
the
CPA-Phos
series
enable
enantioselective
multicomponent
reactions
between
aldehydes,
hydroxylamines
and
cyclic
yne-enones,
leading
to
3,4-dihydro-1H-furo[3,4-d][1,2]oxazines.
This
represents
rare
example
highly
reaction
in
gold(I)
catalysis.
The
proceed
at
low
catalyst
loading
provide
high
yields,
total
diastereoselectivity,
enantiomeric
excesses
up
99%.
Silver-free
conditions
can
be
applied.
method
has
very
broad
scope
as
it
applies
both
aliphatic
aromatic
aldehydes
hydroxylamines,
variety
yne-enone-derived
oximes.
DFT
calculations
complement
this
study
enlighten
reactivity
issues
mechanistic
pathways.
Organic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(13), P. 3307 - 3312
Published: Jan. 1, 2023
An
unprecedented
example
of
skeletal
editing
pyrrolidines
to
1,2-oxazinanes
expands
the
applicability
scope
“single-atom”
skeletal-editing
technologies.
Synthesis,
Journal Year:
2020,
Volume and Issue:
53(06), P. 1046 - 1060
Published: Dec. 21, 2020
Abstract
This
review
summarizes
the
advances
made
on
synthesis
and
functionalization
of
furans
via
gold
catalysis
during
period
between
2016
2020.
A
separate
section
is
dedicated
to
tandem
gold-catalyzed
furans.
1
Introduction
2
Gold-Catalyzed
Synthesis
Furans
2.1
Cycloisomerizations
Alkynyl
Cumulenyl
Alcohols
2.2
Allenyl
Ketones
2.3
Reactions
with
External
Oxidants
2.4
Miscellaneous
3
Functionalization
3.1
Cycloadditions
3.2
Furan
Ring
Decorations
3.3
Involving
Opening
4
Tandem
Furans
4.1
Followed
by
Cycloaddition
4.2
a
Gold
1,3-
or
1,4-Dipole
Intermolecular
Annulation
4.3
Carbene
Trapping
5
Conclusion
