Metal-Free Photoinduced Hydrocyclization of Unactivated Alkenes toward Ring-Fused Quinazolin-4(3H)-ones via Intermolecular Hydrogen Atom Transfer
Organic Letters,
Год журнала:
2023,
Номер
25(10), С. 1683 - 1688
Опубликована: Март 8, 2023
A
visible-light-induced
hydrocyclization
of
unactivated
alkenes
was
developed
using
3CzClIPN
as
the
photocatalyst
to
generate
substituted
α-methyldeoxyvasicinones
and
α-methylmackinazolinones
in
moderate
good
yields.
An
intermolecular
hydrogen
atom
transfer
with
THF
source
involved.
Mechanism
studies
indicated
that
intramolecular
addition
situ
formed
aminal
radical
alkene
generated
polycyclic
quinazolinone.
Язык: Английский
Radical Cascade Cyclization of Alkene‐Tethered Compounds: Versatile Approach towards Ring‐Fused Polycyclic Structures
Asian Journal of Organic Chemistry,
Год журнала:
2023,
Номер
12(5)
Опубликована: Апрель 8, 2023
Abstract
Ring‐fused
polycyclic
structures
widely
exist
in
a
myriad
of
natural
products
and
pharmaceutical
molecules.
Consequently,
the
construction
such
from
readily
available
substrates
becomes
an
important
researching
topic
organic
synthesis.
Triggered
by
addition
radicals
to
(activated
or
unactivated)
double
bonds
alkenes,
subsequent
intramolecular
addition/cyclization
leads
compounds.
Following
this
procedure,
variety
functionalized
ring‐fused
were
formed.
Great
achievements
have
been
witnessed
recently.
Those
works
provided
efficient,
atom
economy,
operational
simple
approaches
toward
versatile
alkene‐based
substrates.
Here,
we
summarized
recent
on
formation
via
radical‐triggered
cascade
reactions
alkenes.
Construction
with
no
less
than
3
fused
rings
developed
during
last
decade
included
Review,
corresponding
mechanisms
also
discussed.
Язык: Английский
Photoinduced palladium-catalyzed radical addition/cyclization of unactivated alkenes with alkyl halides toward alkylated ring-fused quinazolinones
Journal of Organometallic Chemistry,
Год журнала:
2024,
Номер
1008, С. 123066 - 123066
Опубликована: Фев. 18, 2024
Язык: Английский
Synthesis of 2,3-Fused Quinazolinones via the Radical Cascade Pathway and Reaction Mechanistic Studies by DFT Calculations
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(15), С. 10448 - 10459
Опубликована: Июль 17, 2023
An
efficient
radical
cascade
cyclization
of
unactivated
alkenes
toward
the
synthesis
a
series
ring-fused
quinazolinones
has
been
developed
in
moderate
to
excellent
yields
using
commercially
available
ethers,
alkanes,
and
alcohols,
respectively,
under
base-free
condition
short
time
without
transition
metal
as
catalyst.
Notably,
transformations
can
be
carried
out
with
advantages
broad
substrate
scope
high
atomic
economy.
Density
functional
theory
calculations
wavefunction
analyses
were
performed
elucidate
reaction
mechanism.
Язык: Английский
NaI/PPh3-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles
Beilstein Journal of Organic Chemistry,
Год журнала:
2023,
Номер
19, С. 57 - 65
Опубликована: Янв. 16, 2023
A
practical
NaI/PPh
3
-catalyzed
decarboxylative
radical
cascade
cyclization
of
N
-arylacrylamides
with
redox-active
esters
is
described,
which
mediated
by
visible
light
irradiation.
wide
range
substrates
bearing
different
substituents
and
derived
from
ubiquitous
carboxylic
acids,
including
α-amino
were
synthesized
examined
under
this
very
mild,
efficient,
cost
effective
transition-metal-free
synthetic
method.
These
afforded
various
functionalized
oxindoles
featuring
a
C3
quaternary
stereogenic
center.
Mechanistic
experiments
suggest
mechanism.
Язык: Английский
Radical Cascade Cyclization Involving C(sp3)—H Functionalization of Unactivated Cycloalkanes
Chinese Journal of Organic Chemistry,
Год журнала:
2022,
Номер
42(12), С. 4111 - 4111
Опубликована: Янв. 1, 2022
Unactivated
cycloalkane
is
one
of
the
most
extensive
natural
resources,
and
it
great
significance
to
develop
mild
efficient
strategies
achieve
C(sp
3
)-H
unactivated
cycloalkanes.At
same
time,
preparation
ring
compounds
hotspots
in
organic
synthesis
medicinal
chemistry.Because
advantages
conditions
high
reactivity,
radical
cascade
cyclization
involving
functionalization
cycloalkanes
can
simultaneously
meet
above
requirements
synthesize
cyclic
molecules
with
potential
applications
atomic-and
stepeconomy
manner.In
this
review,
from
point
view
iron
catalysis,
copper
metal-catalyst-free
systems,
advances
recent
ten
years
are
summarized.Keywords
cycloalkane;
functionalization;
cyclization;
catalytic
system尽管被邻位氧、氮等原子活化的
键的官能化
已获得了快速的发展
[2]
,
未活化
键官能化的
研究却相对较少,
这主要是由于后者较高的键解离能和
较低的极性所致
[3]
.鉴于上述挑战,
化学工作者针对未
活化环烷烃的官能化进行了不懈探索.定向基团配位或
者金属催化的卡宾/氮宾迁移已被广泛应用于未活化环
烷烃
键官能化
[4]
然而这些方法普遍存在对
较高温度的依赖、借助定向基团的辅助或需要使用昂贵
金属催化剂的局限
[5]
.因此,
在温和条件下尤其是存在
反应活性更高官能团情况时仍能选择性实现未活化环
烷烃的
官能化成为化学工作者关注的焦点之
一.
自由基反应因具有条件温和、反应活性高、官能团
耐受性优良等特点,
为开发未活化环烷烃
键
官能化提供了新思路
[6]
.尤其是,
自由基串联环化已被
证明是一种高效和通用的合成策略,
能高原子和高步骤
经济性地实现未活化环烷烃与不饱和烃之间的反应来
构建各种环状骨架,
为具有环状体系的药物分子和天然
产物合成提供了重要途径
[7]
.
Язык: Английский
Photocatalyzed Acylmethylation/Cyclization of Unactivated Alkenes with Sulfoxonium Ylides towards Acylmethylated Polycyclic Quinazolinones
ChemCatChem,
Год журнала:
2024,
Номер
unknown
Опубликована: Май 16, 2024
Abstract
The
synthesis
of
acylmethylatated
pyrrolo‐quinazolinones
was
developed
via
photo‐induced
cascade
radical
addition/cyclization
N
‐(but‐3‐enyl)quinazolin‐4(3
H
)‐ones
with
sulfoxonium
ylides
using
4CzIPN
as
the
photocatalyst.
This
approach
also
suitable
for
construction
piperidino‐quinazolinones.
protocol
features
mild
conditions,
convenient
operation,
broad
substrate
scope
and
good
functional
group
compatibility.
Язык: Английский
Visible‐Light‐Driven Synthesis of 6‐Aroyl Benzimidazo[1,2‐c]quinazolines from N‐Cyanobenzimidazoles and α‐Keto Acids by Radical Relay Cyclization
European Journal of Organic Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Май 31, 2024
Abstract
A
diverse
array
of
6‐aroyl
benzimidazo[1,2‐
c
]quinazolines
was
successfully
synthesized
using
easily
obtainable
N
‐cyanobenzimidazoles
and
α‐keto
acids,
facilitated
by
photoredox
catalysis.
mechanistic
investigation
revealed
that
this
methodology
might
involve
both
energy
transfer
catalytic
cycles,
generating
acyl
radicals
subsequently
promote
radical
relay
cyclization.
Язык: Английский
Radical Reactions in Water
Опубликована: Ноя. 8, 2024
The
increasing
popularity
of
water
as
an
environmentally
friendly
solvent
in
organic
synthesis
underscores
its
pivotal
role
sustainable
chemistry.
In
this
chapter,
we
mainly
focus
on
radical
reactions
using
a
reaction
medium.
literature
review
presented
herein
categorizes
various
studies
based
distinct
catalytic
modes
and
types,
aiming
to
shed
light
both
challenges
opportunities
burgeoning
field.
Язык: Английский
Recent advancements in iodide/phosphine-mediated photoredox radical reactions
Beilstein Journal of Organic Chemistry,
Год журнала:
2023,
Номер
19, С. 1785 - 1803
Опубликована: Ноя. 22, 2023
Photoredox
catalysis
plays
a
crucial
role
in
contemporary
synthetic
organic
chemistry.
Since
the
groundbreaking
work
of
Shang
and
Fu
on
photocatalytic
decarboxylative
alkylations
2019,
wide
range
transformations,
such
as
alkylation,
alkenylation,
cyclization,
amination,
iodination,
monofluoromethylation,
have
been
progressively
achieved
using
combination
iodide
PPh
3
.
In
this
review,
we
primarily
focus
summarizing
recent
advancements
inexpensive
readily
available
iodide/phosphine-mediated
photoredox
radical
transformations.
Язык: Английский