Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(6), P. 1154 - 1159
Published: Feb. 7, 2024
The
direct
functionalization
of
β-C(sp2)-H
bonds
in
enamides
has
garnered
increasing
attention
within
the
realm
organic
synthesis.
However,
these
remarkable
advancements
are
predominantly
dependent
on
transition
metals;
limited
success
been
achieved
via
organocatalytic
catalysis.
Herein,
we
report
a
CPA-catalyzed
cascade
intramolecular
cyclization
to
synthesize
chiral
dihydropyrimido[1,6-a]indoles
bearing
gem-difluoromethylene.
Moreover,
this
methodology
enables
synthesis
diverse
with
outstanding
enantioselectivities
moderate
high
yields.
The Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 11, 2025
A
Lewis
base-catalyzed
[4
+
3]
annulation
between
dinucleophilic
indole-2-carboxamides
and
Morita-Baylis-Hillmann
(MBH)
carbonates
was
developed
to
access
densely
substituted
indole-1,2-fused
diazepanones.
This
reaction
is
initiated
by
a
N-allylic
alkylation
of
the
indole
scaffold
with
MBH
carbonates,
followed
intramolecular
Michael
cyclization.
Notably,
selectivity
this
process
controlled
removable
o-methoxyphenyl
(OMP)
directing
group
attached
indole-2-carboxamides.
The
wide
scope
substrates,
high
regio-
stereoselectivity,
diverse
transformations
highlight
potential
synthetic
utility
method
in
drug
discovery.
Organic Letters,
Journal Year:
2025,
Volume and Issue:
unknown
Published: May 20, 2025
An
aminocatalytic
asymmetric
(4
+
4)
annulation
of
ynones
and
unsaturated
pyrazolones
is
reported.
This
study
the
first
to
describe
an
enantioselective
synthesis
eight-membered
ether-embedded
4,5-fused
pyrazoles.
The
scope
reaction
broad,
cyclic
ether-containing
pyrazole
products
were
isolated
in
moderate
good
yields
with
high
enantioselectivities.
Green Synthesis and Catalysis,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Jan. 1, 2024
Given
the
significance
of
oxacyclic
frameworks
in
molecular
scaffolds
and
drug
discovery,
it
is
intriguing
to
precisely
construct
manipulate
such
ring
systems
chemical
research.
In
this
area,
intermolecular,
multicomponent
cyclization
for
synthesis
diversely
substituted
seven-membered
oxacycles
under
simple
conditions
still
a
challenge.
Here,
we
report
dual
photoredox/Brønsted
acid
relay
catalytic
strategy
situ
generation
ortho-quinone
methides
subsequent
(4+3)
with
2-indolylalcohols.
one-pot
reaction,
two
C-C
one
C-O
bonds
are
formed,
providing
de
novo
access
various
biologically
important
indole-fused,
oxygen-containing
heterocycles.
By
virtue
chiral
phosphoric
acid,
an
asymmetric
version
can
also
be
achieved
good
excellent
levels
enantioselectivity
(up
96:4
er).
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(6), P. 1154 - 1159
Published: Feb. 7, 2024
The
direct
functionalization
of
β-C(sp2)-H
bonds
in
enamides
has
garnered
increasing
attention
within
the
realm
organic
synthesis.
However,
these
remarkable
advancements
are
predominantly
dependent
on
transition
metals;
limited
success
been
achieved
via
organocatalytic
catalysis.
Herein,
we
report
a
CPA-catalyzed
cascade
intramolecular
cyclization
to
synthesize
chiral
dihydropyrimido[1,6-a]indoles
bearing
gem-difluoromethylene.
Moreover,
this
methodology
enables
synthesis
diverse
with
outstanding
enantioselectivities
moderate
high
yields.
