Angewandte Chemie,
Journal Year:
2022,
Volume and Issue:
134(31)
Published: May 10, 2022
Abstract
Die
stereospezifische
[1,5]‐Kohlenstoffverschiebung
der
C3‐Ammoniumenolate
wird
beschrieben.
Gemäß
mechanistischen,
kinetischen
und
rechnergestützten
Experimenten
verläuft
die
neuartige
Umlagerung
über
ein
transientes
C3‐Ammoniumenolat.
Dies
durch
eine
katalysierte
intramolekulare
Aza‐Michael‐Addition
erzeugt.
anschließende
[1,5]‐sigmatrope
Kohlenstoffmigration
bildet
entsprechenden
Tetrahydrochinolin‐4‐one
in
61–98
%
Ausbeute
mit
exzellenten
Diastereoselektivitäten
von
d.r.
>99
:
1.
Synthesis,
Journal Year:
2024,
Volume and Issue:
56(13), P. 2047 - 2058
Published: March 6, 2024
Abstract
Michael-type
hydroaminations
of
acrylonitrile,
phenyl
vinyl
sulfone,
and
dimethyl
maleate
were
realized
using
arylamines
catalyzed
independently
by
Yb(OTf)3
Tb(OTf)3
to
give
the
desired
β-aminonitriles,
β-amino
sulfones,
aspartates,
respectively,
in
moderate
excellent
yields.
The
reactions
carried
out
toluene
for
t-BuOMe
Tb(OTf)3,
all
performed
at
100
°C.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(26), P. 5571 - 5576
Published: June 26, 2024
Double
aza-Michael
addition
(DAM)
has
become
an
emerging
strategy
for
the
construction
of
two
carbon–nitrogen
bonds
in
a
single
step,
which
can
significantly
simplify
synthesis
N-heterocycles.
Hitherto,
their
asymmetric
catalytic
genre
remains
unattempted.
Herein,
we
describe
judicious
design
organocatalytic
enantioselective
desymmetric
double
cascade
to
access
series
functionalized
fused
morpholines
with
excellent
yields
and
diastereo-
enantioselectivities.
A
one-pot
telescopic
was
demonstrated
bridged
triheterocyclic
compound.
In
addition,
scale-up
various
attractive
postsynthetic
modifications
title
products
amplify
significance
current
methodology.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(8), P. 1647 - 1651
Published: Feb. 17, 2022
The
highly
enantioselective
aza-Michael
reaction
of
tert-butyl
β-naphthylmethoxycarbamate
to
cyclic
enones
has
been
accomplished
by
using
a
new
cinchona
alkaloid
derived
C(9)-urea
ammonium
catalyst
under
phase-transfer
catalysis
conditions
with
up
98%
ee
at
0
°C.
resulting
adducts
can
be
converted
versatile
intermediates
selective
deprotection
and
the
1,3-aminoalcohols
diastereoselective
reduction
32:1,
which
have
widely
used
as
important
pharmacophores
in
pharmaceutical
development.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(31)
Published: May 10, 2022
The
stereospecific
sigmatropic
[1,5]
carbon
shift
of
C3
ammonium
enolates
is
discovered.
According
to
mechanistic,
kinetic
and
computational
experiments,
this
new
rearrangement
proceeds
via
the
catalytic
generation
a
transient
enolate
by
intramolecular
aza-Michael
addition.
This
intermediate
rapidly
undergoes
migration
furnish
respective
tetrahydroquinoline-4-ones
with
excellent
diastereoselectivities
d.r.
>99
:
1
in
61-98
%
yield.
Organic & Biomolecular Chemistry,
Journal Year:
2024,
Volume and Issue:
22(12), P. 2423 - 2434
Published: Jan. 1, 2024
Cholinium
α-amino
carboxylates,
which
debuted
in
the
ionic
liquid
arena
over
a
decade
ago,
exhibit
superior
stability
and
suitable
physical
properties
relative
to
other
RTILs.
Although
synthetic
pursuits
such
media,
leveraging
their
dual
role
as
solvents
catalysts,
have
been
scarce
so
far,
we
herein
illustrate
catalytic
advantage
aza-Michael
reactions
terms
of
low
loading,
acceleration
improved
yields
with
respect
conventional
conditions
imidazolium-based
ILs.
These
highly
structured
salts
most
likely
act
through
multiple
cooperative
non-covalent
interactions.
mechanistic
features
also
investigated
high-level
computational
analyses
well.
Synlett,
Journal Year:
2022,
Volume and Issue:
34(06), P. 572 - 600
Published: Aug. 8, 2022
Abstract
The
application
of
bifunctional
organocatalysts
in
organic
chemistry
has
advanced
remarkably
owing
to
their
high
stability
moisture
and
air,
relatively
low
toxicity,
ease
handling,
recoverability.
Among
chiral
organocatalysts,
squaramides
have
emerged
as
a
privileged
catalyst
recent
years.
This
review
article
presents
comprehensive
report
on
fine-tunable
squaramide-catalyzed
sulfa-Michael
addition,
which
is
based
upon
synchronous
interplay
synergistic
‘electrophilic–nucleophilic’
dual
activation
strategies
via
multiple
H-bonding
interactions
for
the
construction
both
common
complex
molecular
entities
bearing
stereocenters.
Mechanistic
discussions
are
kept
brief,
but
significant
understandings
been
recorded.
contribution
squaramide
C–S
bonds
addition
applied
medicinal,
natural,
industrial
chemistry.
Attention
focused
summarizing
progress
made
asymmetric
subsequent
cascade/domino
reaction
sequences
between
2011
2022.
1
Introduction
2
Quinine-Squaramide
Organocatalysis
3
Iminophosphorane-Squaramide
4
Chinchona-Squaramide
5
trans-1,2-Diaminocyclohexane-Squaramide
6
Conclusion
Asian Journal of Organic Chemistry,
Journal Year:
2021,
Volume and Issue:
11(1)
Published: Nov. 12, 2021
Abstract
An
effective
organocatalytic
protocol
toward
the
assembly
of
symmetrical
and
unsymmetrical
2,6‐diarylpyridines
is
demonstrated.
The
reaction
proceeds
through
decarboxylation
amino
acid
dual
C(sp
3
)−H
bond
oxidation
carbonyl
compounds.
Catalyst
screening
revealed
that
explicit
choice
L‐proline
could
lead
formation
product
with
maximum
yield
selectivity.
developed
process
appears
operational
simplicity
consistent
broad
range
functional
groups.
