Organic Letters,
Год журнала:
2019,
Номер
21(18), С. 7415 - 7419
Опубликована: Сен. 5, 2019
A
remote
stereocontrolled
1,8-conjugate
addition
of
thiazolones
to
propargylic
aza-p-quinone
methides
formed
from
alcohols
has
been
developed
with
the
aid
a
chiral
phosphoric
acid,
and
this
represents
first
report
on
organocatalytic
1,8-addition
methides.
Notably,
activation
protocol
enables
construction
vicinal
sulfur-containing
quaternary
carbon
stereocenters
axially
tetrasubstituted
allenes
promotes
chemistry
acids.
Organic Letters,
Год журнала:
2019,
Номер
21(19), С. 8127 - 8131
Опубликована: Сен. 23, 2019
In
contrast
to
the
well-explored
quinone
methides
(QMs)
and
aza-ortho-QMs,
aza-para-QMs
have
been
rarely
studied
in
terms
of
their
asymmetric
transformations.
Herein,
a
highly
efficient
enantioconvergent
1,8-addition
is
described.
Featuring
remarkable
remote
stereocontrol,
this
reaction
provides
expedient
access
chiral
tetrasubstituted
allenes
bearing
an
adjacent
all-carbon
quaternary
stereocenter
with
high
enantioselectivity
diastereoselectivity.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(40)
Опубликована: Авг. 12, 2022
Here
we
report
a
new
type
of
chiral
all-carbon
tetrasubstituted
VQMs
generated
via
phosphoric
acids
catalyzed
nucleophilic
addition
2-alkynylnaphthols
to
o-quinone
methides
or
imines,
which
can
be
captured
intramolecularly
as
result
cycloaddition
reaction.
A
class
naphthyl-2H-chromenes
bearing
axially
and
centrally
elements
quinone-naphthols
were
prepared
efficiently
with
good
excellent
yields,
diastereoselectivities
enantioselectivities.
Noteworthy,
the
enantioselective
alkynylnaphthols
proceeded
[2+2]
cycloaddition,
followed
by
retro-4π-electrocyclization
6π
re-cyclization.
While
imines
sequential
[2+4]
an
auto
oxidation
Moreover,
obtained
naphthols
converted
into
valuable
phosphine
ligands
other
functional
molecules.
Chinese Journal of Chemistry,
Год журнала:
2022,
Номер
41(1), С. 27 - 36
Опубликована: Сен. 16, 2022
Comprehensive
Summary
A
new
class
of
m
‐hydroxybenzyl
alcohols
has
been
designed
as
competent
three‐carbon
building
blocks
and
achieved
their
application
in
2‐indolylmethanol‐involved
regioselective
(3
+
3)
cycloadditions
under
the
catalysis
Brønsted
acids.
By
this
appoach,
a
series
indole‐fused
six‐membered
cycloadducts
have
synthesized
overall
good
yields
(up
to
98%)
with
excellent
regioselectivity
(all
>95:
5
rr),
thus
affording
powerful
method
for
construction
rings.
Moreover,
catalytic
asymmetric
version
cycloaddition
preliminarily
investigated,
which
revealed
potential
reaction
constructing
chiral
rings
an
enantioselective
manner.
This
work
not
only
accomplished
first
design
reactants,
but
also
represents
cycloadditions.
In
addition,
provides
example
C3‐nucleophilic
2‐indolylmethanols,
will
substantially
enrich
chemistry
2‐indolylmethanols.
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(16), С. 7374 - 7381
Опубликована: Апрель 13, 2022
Nonactivated
arenes,
such
as
benzene
derivatives,
are
chemically
inert
due
to
their
intrinsic
aromaticity
and
low
polarity.
The
catalytic
asymmetric
dearomatization
(CADA,
coined
by
You
co-workers)
of
the
nonactivated
arenes
represents
a
formidable
challenge.
We
herein
demonstrated
an
organocatalytic
dearomatizing
hetero-Diels–Alder
reaction
derivatives.
tunable
regioselectivity
this
strategy
allowed
delivery
diversity
stereochemically
complex
polycyclic
compounds
oxahelicenes
with
excellent
stereoselectivity.
high
complexity
three-dimensionality
products
crucial
for
potential
applications
in
materials
science
drug
discovery.
Mechanistic
studies
suggested
that
proceeds
through
chiral
tetra-substituted
vinylidene
ortho-quinone
methide
(VQM)
intermediate,
which
is
extremely
active
overcome
loss
derivatives
concomitant
chirality
transfer.
Synthesis,
Год журнала:
2022,
Номер
54(14), С. 3125 - 3141
Опубликована: Фев. 24, 2022
Abstract
This
review
summarizes
recent
developments
in
the
area
of
Brønsted
acid
catalyzed,
enantioselective
cycloadditions
ortho-quinone
methides,
methide
imines
as
well
heterocyclic
indole-
and
pyrrole-based
methides.
In
a
straightforward
single-step
transformation
complex
polycyclic
N-
O-heterocyclic
scaffolds
are
accessible,
with
typically
good
yields
excellent
stereocontrol,
from
simple
benzyl
heterobenzyl
alcohols
upon
acid-catalyzed
dehydration.
The
transient
precursors
hydrogen-bonded
to
chiral
which
controls
enantioselectivity
process.
1
Introduction
2
Cycloadditions
ortho-Quinone
Methides
2.1
Acid
Catalyzed
Processes
2.2
Cooperative
Acid/Transition-Metal-Catalyzed
3
Methide
Imines
4
Indolyl-3-methides
5
Indolyl-2-methides
5.1
5.2
6
Pyrrolyl-2-methides
7
Pyrrolyl-3-methides
8
Conclusions
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(23), С. 16020 - 16027
Опубликована: Май 30, 2024
The
quest
for
more
efficient,
user-friendly,
and
less
wasteful
topological
transformations
remains
a
significant
challenge
in
the
realm
of
postassembly
modifications.
In
this
article,
high
yields
two
molecular
trefoil
knots
(Rh-1,
Ir-1)
were
obtained
using
ligand
3,6-bis(3-(pyridin-4-yl)phenyl)-1,2,4,5-tetrazine
(L1)
with
reactive
tetrazine
units
binuclear
half-sandwich
organometallic
[Cp*2M2(μ-TPPHZ)(OTf)2](OTf)2
(Rh-B,
M
=
RhIII;
Ir-B,
IrIII).
2,5-Norbornadiene
was
used
as
an
inducer
Diels–Alder
click
reaction
to
modulate
rapidly
efficiently
transformation
Trefoil
Solomon
links.
However,
key
achieving
structural
change
is
subtle
increase
site
steric
pyridazine
fragments
(L2),
which
allows
structures
spread
bend
three-dimensional
space,
confirmed
by
single-crystal
X-ray
diffraction,
ESI-TOF/MS,
elementary
analysis
detailed
solution-state
NMR
techniques.
