Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(15), P. 3069 - 3074
Published: April 1, 2024
Free
radical
three-component
nitration/spirocyclization
of
unsaturated
sulfonamides/amides
with
tert-butyl
nitrite
was
developed
for
the
construction
diverse
NO2-revised
4-azaspiro[4.5]decanes.
This
tandem
system
featured
metal-free
participation,
simple
operation,
good
selectivity/yields,
and
a
green/low-cost
O
source.
Meanwhile,
one
nitro-containing
complex
molecule
scaled-up
operation
were
performed
well
to
test
synthetic
potential
cascade
reaction.
Isotopic
labeling,
inhibition
experiments,
DFT
analysis
carried
out
gain
insight
into
reaction
process.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
13(9), P. 2783 - 2788
Published: Jan. 1, 2022
Despite
indisputable
progress
in
the
development
of
electrochemical
transformations,
electrocatalytic
annulations
for
synthesis
biologically
relevant
three-dimensional
spirocyclic
compounds
has
as
yet
not
been
accomplished.
In
sharp
contrast,
herein,
we
describe
palladaelectro-catalyzed
C-H
activation/[3
+
2]
spiroannulation
alkynes
by
1-aryl-2-naphthols.
Likewise,
a
cationic
rhodium(iii)
catalyst
was
shown
to
enable
electrooxidative
[3
spiroannulations
via
formal
C(sp3)-H
activations.
The
versatile
featured
broad
substrate
scope,
employing
electricity
green
oxidant
lieu
stoichiometric
chemical
oxidants
under
mild
conditions.
An
array
enones
and
diverse
spiropyrazolones,
bearing
all-carbon
quaternary
stereogenic
centers
were
thereby
accessed
user-friendly
undivided
cell
setup,
with
molecular
hydrogen
sole
byproduct.
Green Chemistry,
Journal Year:
2023,
Volume and Issue:
25(9), P. 3543 - 3548
Published: Jan. 1, 2023
An
electrochemical
electrophilic
bromination/spirocyclization
of
N
-benzyl-acrylamides
to
brominated
2-azaspiro[4.5]decanes
with
2-bromoethan-1-ol
as
the
brominating
reagent
has
been
developed.
Organic Letters,
Journal Year:
2021,
Volume and Issue:
23(17), P. 6691 - 6696
Published: Aug. 16, 2021
A
novel
and
efficient
strategy
for
trifluoromethylthiolation
dearomatization
of
activated
alkynes
with
stable
readily
available
AgSCF3
has
been
developed.
Reported
herein
is
the
unprecedented
electrochemical
generation
SCF3
radical
in
absence
persulfate
synthesis
SCF3-containing
spiro[5,5]trienones
good
yields
via
a
6-exo-trig
cyclization.
Chemistry - An Asian Journal,
Journal Year:
2023,
Volume and Issue:
18(9)
Published: March 15, 2023
Electrochemical
dearomative
spirocyclization
serves
as
a
green
and
sustainable
approach
to
convert
the
flat,
two-dimension
aromatic
feedstock
into
value-added
three-dimension
spirocyclic
architectures.
This
review
highlights
recent
advances,
emphasizes
mechanistic
discussions,
showcases
synthetic
applications
of
this
emerging
versatile
powerful
transformation.
The Journal of Organic Chemistry,
Journal Year:
2021,
Volume and Issue:
86(23), P. 17071 - 17081
Published: Nov. 22, 2021
Electrooxidative-induced
synthesis
of
structurally
diverse
seleno-dibenzocyclohepten-5-ones
and
seleno-spiro[5.5]trienones
by
selenylative
carbannulation
biaryl
ynones
with
diaryl
diselenide
has
been
developed.
The
switchable
reactivity,
intramolecular
ortho-annulation
or
dearomative
ipso-annulation,
is
directed
the
substituent
present
on
ortho-aryl
group
aryl-ynone.
prominent
features
this
method
include
metal-free,
external
chemical
oxidant-free
conditions,
readily
accessible
substrates.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
61(9)
Published: Dec. 28, 2021
We
describe
here
a
Ni-catalyzed
intermolecular
carbo-fluoromethylation
of
alkynes
with
aliphatic
halides
and
fluoromethyl
(BrCF2
H
ICH2
F)
in
the
presence
zinc,
enabling
facile
selective
access
to
diverse
range
biologically
valuable
CF2
H/CH2
F-incorporated
alkenes
excellent
regio-
stereoselectivity.
Notably,
merging
intramolecular
radical
cyclization
coupling
enables
expedient
constructions
lactones
lactams
high
efficiency
selectivity.
Mechanistic
studies
disclose
that
this
catalytic
protocol
proceeds
via
addition
an
alkyne
followed
by
unit.
The Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
87(13), P. 8697 - 8708
Published: June 9, 2022
An
electrochemical
dearomatizing
spirocyclization
of
alkynes
with
dimethyl
2-benzylmalonates
for
the
preparation
spiro[4.5]deca-trienones
has
been
developed.
This
approach
adopts
ferrocene
(Cp2Fe)
as
an
electrocatalyst
to
produce
carbon-centered
radical
intermediates
from
C–H-based
malonates,
which
obviates
forthputting
noble-metal
reagents,
sacrificial
chemical
oxidants
and
2-bromomalonates.
A
wide
variety
spiro
compounds
are
efficiently
prepared
satisfactory
results
under
mild
conditions.
Advanced Synthesis & Catalysis,
Journal Year:
2022,
Volume and Issue:
364(9), P. 1537 - 1542
Published: March 11, 2022
Abstract
Iron‐catalyzed
cascade
silyl
radical
addition/6‐
exo
‐trig
cyclization/dearomatization
of
biaryl
ynones
has
been
developed.
This
approach
uses
silane
as
the
precursor
well
silylation
reagent,
1,10‐phenanthroline
ligand,
and
tert
‐butyl
hydroperoxide
(TBHP)
oxidant.
By
employing
this
tandem
process,
a
series
silylated
spiro[5.5]trienones
were
prepared.
magnified
image
Organic & Biomolecular Chemistry,
Journal Year:
2022,
Volume and Issue:
20(33), P. 6659 - 6666
Published: Jan. 1, 2022
A
selective
polychloromethylation
and
halogenation
reaction
of
alkynes
via
a
radical
addition/spirocyclization
cascade
sequence
was
developed,
in
which
applying
polyhaloalkanes
as
the
precursor
polyhalomethyl
halogen
radicals.
