Abstract
A
formal
[4+3]
cycloaddition
of
2‐alkylidenetrimethylene
carbonates
with
quinazoline‐derived
azomethine
imines
is
described.
Under
Pd
catalysis,
the
reaction
works
efficiently
under
room
temperature
to
afford
angular
quinazoline‐fused
seven‐membered
N,N,O
‐heterocycles.
variety
cyclic
and
were
well
tolerated
mild
conditions.
This
work
demonstrates
synthetic
utility
decarboxylative
cycloadditions
for
synthesis
polycyclic
aromatic
molecules.
Organic Chemistry Frontiers,
Год журнала:
2024,
Номер
11(10), С. 2864 - 2869
Опубликована: Янв. 1, 2024
A
novel
palladium-catalyzed
[4
+
4]
cycloaddition
of
2-pyrones
with
2-alkylidenetrimethylene
carbonates
has
been
developed
for
the
synthesis
bridged
eight-membered
oxygen
heterocycles
in
good
yields
and
excellent
stereoselectivities.
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
88(1), С. 97 - 105
Опубликована: Дек. 9, 2022
An
efficient
method
for
the
construction
of
hydrocarbazoles
bearing
three
continuous
sterically
hindered
stereocenters,
two
quaternary
and
one
tertiary,
via
a
highly
diastereoselective
palladium-catalyzed
[4
+
2]-cycloaddition/dearomatization
3-nitroindoles
has
been
developed.
The
cycloaddition
occurs
at
ambient
conditions
with
1,4-zwitterionic
intermediate,
in
situ
generated
from
γ-methylidene-δ-valerolactones.
further
synthetic
utility
this
is
demonstrated
by
multifaceted
transformations
possible
products.
catalytic
asymmetric
aspect
transformation
also
explored.
Chinese Journal of Organic Chemistry,
Год журнала:
2023,
Номер
43(8), С. 2864 - 2864
Опубликована: Янв. 1, 2023
A
Pd-catalyzed
decarboxylation
strategy
for
the
efficient
synthesis
of
cyclohepta
[b]indoles
in
good
yields
with
to
excellent
enantioselectivities
and
moderate
diastereoselectivities
is
reported.In
this
procedure,
viny
indoloxazolidones
were
activated
by
Pd
catalyst
generate
zwitterionic
intermediates
situ,
which
then
trapped
electro-deficient
diene
species
via
asymmetric
[3＋4]
cycloaddition
process.
Molecules,
Год журнала:
2023,
Номер
28(11), С. 4410 - 4410
Опубликована: Май 29, 2023
[3
+
2]
Cycloaddition
reactions
of
heteroaromatic
N-ylides
with
electron-deficient
olefins
have
been
developed.
The
N-ylides,
in
situ
generated
from
N-phenacylbenzothiazolium
bromides,
can
smoothly
react
maleimides
under
very
mild
conditions,
affording
fused
polycyclic
octahydropyrrolo[3,4-c]pyrroles
good-to-excellent
isolated
yields.
This
reaction
concept
could
also
be
extended
to
3-trifluoroethylidene
oxindoles
and
benzylidenemalononitriles
as
for
accessing
highly
functionalized
polyheterocyclic
compounds.
A
gram-scale
experiment
was
carried
out
verify
the
practicability
methodology.
Organic & Biomolecular Chemistry,
Год журнала:
2023,
Номер
21(48), С. 9507 - 9518
Опубликована: Янв. 1, 2023
This
review
summarizes
Pd-catalyzed
oxa-[4
+
n
]
dipolar
cycloadditions
of
1,4-O/C
dipoles
with
diverse
dipolarophiles,
affording
five-
to
nine-membered
O-heterocycles.
Abstract
Cycloaddition
reactions
serve
as
exceptionally
useful
strategy
to
provide
atom‐economical,
efficient
and
practical
access
complex
molecules
from
simple
starting
materials.
The
[4+2]‐cycloaddition
reaction
allows
for
the
stereospecific
construction
of
six‐membered
carbo‐/heterocycles.
catalyzed
by
transition
metals
are
potent
methods
rapid
highly
functionalized
molecular
frameworks.
This
review
article
summarizes
different
reports
on
transition‐metal
involving
various
such
Pd,
Cu,
Rh,
Au,
Fe,
Ni,
Sc,
Sn,
Hf,
Ag,
Mn,
Dy,
Co
etc.
straightforward
pharmaceutically
active
heterocycles.
An
emphasis
is
laid
mechanistic
insights
highlight
unique
application
novel
processes
transition‐metals
in
these
transformations
build
intricate
polycyclic
structures.
Chemistry - A European Journal,
Год журнала:
2024,
Номер
30(34)
Опубликована: Апрель 15, 2024
Dearomative
Diels-Alder
cycloadditions
between
nitroarenes
and
2-trimethylsilyloxycyclohexadiene
are
carried
out
under
high
pressure
at
room
temperature
in
the
absence
of
any
chemical
promoter.
Reactions
performed
with
different
arenes,
including
highly
aromatic
naphthalenes
quinolines.
They
lead
to
3D-scaffolds
exquisite
exo-diastereoselectivity.
The
exo
approach
is
characterized
by
lower
distortion
substrates
a
late
TS
more
favorable
orbital
interactions
presumably
nitro
group
dienic
part,
explaining
stereoselectivity.
Chinese Journal of Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 16, 2024
Comprehensive
Summary
We
report
a
palladium‐catalyzed
asymmetric
[4+4]
cycloaddition
reaction
between
2‐alkylidenetrimethylene
carbonate
and
electron‐deficient
indole‐2,3‐quinodimethanes
(
IQDMs
).
This
features
exclusive
regioselectivity,
high
yield
(up
to
98%),
excellent
enantioselectivity
95%
ee),
easy
scale‐up
without
any
loss
of
efficiency,
making
it
valuable
for
the
synthesis
indole‐fused
eight‐membered
oxa‐rings.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(5), С. 3012 - 3021
Опубликована: Фев. 22, 2023
Tetrahydropyranones
are
synthesized
from
3-bromobut-3-en-1-ols
and
aldehydes
in
good
yields
with
excellent
diastereoselectivity
at
−35
°C.
The
reaction
involves
an
initial
formation
of
a
most
stable
six-membered
chairlike
tetrahydropyranyl
carbocation
followed
by
nucleophilic
attack
the
hydroxyl
group
subsequent
elimination
HBr
to
give
tetrahydropyranone.
carbonyl
moiety
tetrahydropyranone
is
converted
enol
ether
esters
using
Wittig
reaction.
It
also
transformed
into
4-hydroxy-2,6-disubstituted
tetrahydropyran
2,4-
4,6-cis
configuration
lithium
aluminum
hydride
up
96%
diastereoselectivity.
Furthermore,
methodology
extended
toward
synthesis
novel
anticancer
aminoguanidine
compounds.
