Organic Reaction Mechanisms/Organic reaction mechanisms,
Journal Year:
2020,
Volume and Issue:
unknown, P. 501 - 526
Published: July 24, 2020
This
Chapter
Contains
Sections
titled:
2
+
2-Cycloaddition
3-Cycloaddition
4-Cycloaddition
Miscellaneous
References
chapter
presents
an
extensive
review
of
the
use
organocatalysts,
such
as
diarylpropinol
silyl
ethers,
in
asymmetric
cycloaddition
reactions.
The
includes
2+2-,
3+2-,
and
4+2-cycloadditions
which
do
not
require
loss
a
leaving
group
to
form
cyclic
compound.
reports
comprehensive
gold-catalysed
enantioselective
annulations
including
cycloadditions,
cyclizations
C–C
multiple
bonds
with
tethered
nucleophiles,
cycloisomerization
or
cyclization
enynes,
tandem
annulations.
photosensitized
regioselective
2+2-cycloaddition
cinnamates,
chalcones,
styrenes
produced
substituted
cyclobutanes
high
yields
good
regioselectivity.
stereoselective
organo-catalysed
3+2-cycloaddition
donor–acceptor
cyclopropanes
mono-
poly-substituted
nitroolefins
functionalized
cyclopentanes
three
contiguous
stereocentres
stereoselectivity.
A
4+2-cycloaddition
reactions
ynamines
ynamides
providing
complex
aromatics
N-containing
heterocycles
single
step
has
been
published.
Synthesis,
Journal Year:
2020,
Volume and Issue:
53(01), P. 65 - 78
Published: Sept. 11, 2020
Abstract
This
Short
Review
highlights
various
synthetic
approaches
to
bridged
azabicyclic
ring
systems
containing
seven-membered
carbocyclic
rings.
Such
are
common
a
number
of
biologically
active
natural
products.
The
in
such
is
generally
formed
one
four
ways:
1)
cyclization
an
acyclic
precursor;
2)
expansion
or
rearrangement
different
size;
3)
cycloaddition;
and
4)
use
building
block
with
the
already
present.
Representative
examples
each
approach
from
both
total
synthesis
methodological
studies
discussed,
emphasis
on
work
published
last
twenty
years.
1
Introduction
2
Cyclization
Reactions
3
Ring
Expansions
Rearrangements
4
Cycloadditions
5
Strategies
Involving
Seven-Membered
Building
Blocks
6
Conclusion
Chinese Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
43(9), P. 3078 - 3078
Published: Jan. 1, 2023
There
are
two
different
ring-opening
modes
of
aziridines:
aziridines
via
carbon-nitrogen
bond
cleavage,
and
carbon-carbon
cleavage.Among
them,
the
reaction
cleavage
has
been
reported
in
many
reviews.The
cycloaddition
reactions
donor-acceptor
(D-A)
recent
20
years
mainly
summarized.Under
some
proper
catalysts,
D-A
yield
azomethine
ylides,
which
can
undergo
[3＋n]
with
aldehydes,
imines,
alkenes,
alkynes,
indoles
etc.
Synthetic Communications,
Journal Year:
2020,
Volume and Issue:
50(21), P. 3245 - 3255
Published: Aug. 3, 2020
This
study
describes
the
synthesis
of
novel
polycyclic
spiropyrrolidine
oxindoles
through
1,3-dipolar
cycloaddition
azomethine
ylides
generated
in
situ
with
3-(arylmethylene)-indolin-2-ones.
Effect
substituents
and
various
dipolarophiles
on
reactivity,
as
well
products
regio-
stereoselectivity
was
investigated.
Advanced Synthesis & Catalysis,
Journal Year:
2021,
Volume and Issue:
364(3), P. 622 - 636
Published: Nov. 6, 2021
Abstract
Herein,
we
report
the
pyrrolidine‐catalyzed
annulation
reaction
of
p
‐quinone
monoacetals
with
naphthols
at
room
temperature.
The
is
also
extended
to
including
4‐hydroxycoumarin,
4‐hydroxy‐1‐methylcarbostyril,
4‐hydroxycarbostyril,
and
several
β‐ketoesters
as
nucleophiles,
thereby
providing
a
collection
bridged
cyclic
compounds
bearing
2‐oxabicyclo[3.3.1]nonane
skeletons
in
41–96%
yields.
can
be
adapted
gram‐scale
synthesis,
transformations
obtained
products
are
demonstrated
for
preparation
polycyclic
that
may
find
utility
related
fields.
Mechanism
studies
indicate
engagement
iminium
intermediate
reaction,
ring
enamine
observed
by
NMR.
magnified
image
Organic Letters,
Journal Year:
2019,
Volume and Issue:
21(17), P. 6815 - 6820
Published: Aug. 26, 2019
Design
of
a
unique
reaction
pathway
in
transition-metal-catalyzed
1,6-enynes
cyclization
to
construct
valuable
synthetic
motifs
is
significant
challenge
organic
chemistry.
Herein,
we
report
Ru(II)-catalyzed
formal
[3
+
2]
cycloaddition
as
an
efficient
method
prepare
unprecedented
bicyclo[3.3.0]octenes
from
readily
available
(E)-1,6-enynes.
Mechanistic
studies
based
on
the
deuterium
labeling
experiments
and
DFT
calculation
disclose
reasonable
mechanistic
pathway,
where
ruthenacyclopentene
generated
by
ene-yne
oxidative
undergoes
sequential
ß-hydride
elimination
intramolecular
hydroruthenation
form
ruthenacyclohexene,
producing
desirable
bicyclo[3.3.0]octenes.
Chinese Journal of Chemistry,
Journal Year:
2019,
Volume and Issue:
37(7), P. 695 - 699
Published: May 16, 2019
Summary
of
main
observation
and
conclusion
The
first
LA‐catalyzed
[3
+
2]IMCC
GDA‐epoxides
with
carbon‐carbon
double
bonds
has
been
developed.
This
provides
an
efficient
general
strategy
for
construction
bridged
oxa‐[
n
.2.1]
skeletons.
A
novel
S
N
‐like
mechanism
through
a
bond
cleavage
epoxide
ring
proposed.
Asian Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
13(7)
Published: March 20, 2024
Abstract
2‐Arylsulfonyl‐2‐azabicyclo[
2.2.1
]hept‐5‐enes,
synthesized
via
the
cycloaddition
of
chloral‐
or
dichloro(phenyl)acetaldehyde
N
‐arylsulfonylimines
to
cyclopentadiene,
undergo
Wagner‐Meerwein
rearrangement
under
action
bromine
chlorine
afford
3‐polychloro‐6,7‐dyhalogenated
2‐arylsulfonylazabicyclo[
]heptanes.
