Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(31)
Published: May 20, 2024
Abstract
Neighboring
group
participation,
the
assistance
of
non‐conjugated
electrons
to
a
reaction
center,
is
fundamental
phenomenon
in
chemistry.
In
framework
nucleophilic
substitution
reactions,
neighboring
participation
known
cause
rate
acceleration,
first
order
kinetics
(S
N
1),
and
retention
configuration.
The
latter
result
double
inversion:
one
when
displaces
leaving
group,
second
nucleophile
substitutes
group.
This
powerful
control
stereoretention
has
been
widely
used
organic
synthesis
for
more
than
century.
However,
may
also
lead
inversion
configuration,
which
often
overlooked.
Herein,
we
review
this
unique
mode
stereoinversion,
dividing
relevant
reactions
into
three
classes
with
aim
introduce
fresh
perspective
on
different
modes
stereoinversion
via
as
well
factors
that
stereochemical
outcome.
Science Advances,
Journal Year:
2024,
Volume and Issue:
10(2)
Published: Jan. 12, 2024
Prediction
of
the
outcome
ring
opening
small
organic
rings
under
cationic
conditions
can
be
challenging
due
to
intermediacy
nonclassical
carbocations.
For
example,
solvolysis
cyclobutyl
or
cyclopropylmethyl
derivatives
generates
up
four
products
on
nucleophilic
capture
elimination
via
cyclopropylcarbinyl
and
bicyclobutonium
ions.
Here,
we
show
that
such
reaction
outcomes
controlled
by
subtle
changes
structure
carbocation.
Using
bicyclo[1.1.0]butanes
as
cation
precursors,
regio-
stereochemistry
is
shown
depend
degree
nature
substituents
intermediates.
Reaction
are
rationalized
using
computational
models,
resulting
in
a
flowchart
predict
product
formation
from
given
precursor.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(3)
Published: Nov. 22, 2022
An
efficient
method
for
the
stereoselective
construction
of
tertiary
C-O
bonds
via
a
stereoinvertive
nucleophilic
substitution
at
quaternary
carbon
stereocenter
cyclopropyl
carbinol
derivatives
using
water,
alcohols
and
phenols
as
nucleophiles
has
been
developed.
This
reaction
proceeds
under
mild
conditions
tolerates
several
functional
groups,
providing
new
access
to
formation
highly
congested
homoallyl
ethers.
Organic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(9), P. 2346 - 2358
Published: Jan. 1, 2023
In
this
Review,
the
underrecognized
utilities
of
cyclopropylcarbinyl
cation
chemistry
are
summarized
in
cyclopropane
synthesis
and
skeletal
rearrangements,
their
applications
natural
product
total
highlighted.
Organic & Biomolecular Chemistry,
Journal Year:
2023,
Volume and Issue:
21(13), P. 2709 - 2714
Published: Jan. 1, 2023
We
report
a
new
gate
for
changing
photo
inactive
compounds
into
photocatalysts
with
easy
operation,
good
tolerance
of
functional
groups,
and
considerable
yield.
demonstrate
the
synthesis
natural
products
Azacephalandole
A
Cephalandole
in
high
yields.
The Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
88(11), P. 6947 - 6954
Published: May 4, 2023
The
synthesis
of
quaternary
homoallylic
halides
and
trichloroacetates
from
cyclopropylcarbinols,
as
reported
by
Marek
(J.
Am.
Chem.
Soc.2020,
142,
5543-5548),
is
one
the
few
examples
stereospecific
nucleophilic
substitution
involving
chiral
bridged
carbocations.
However,
for
phenyl-substituted
substrates,
poor
specificity
observed
mixtures
diastereomers
are
obtained.
To
understand
nature
intermediates
involved
explain
loss
certain
we
have
performed
a
computational
investigation
reaction
mechanism
using
ωB97X-D
optimizations
DLPNO-CCSD(T)
energy
refinements.
Our
results
indicate
that
cyclopropylcarbinyl
cations
stable
in
this
reaction,
while
bicyclobutonium
structures
high-energy
transition
not
involved.
Instead,
multiple
rearrangement
pathways
were
located,
including
ring
openings
to
cations.
activation
barriers
required
reach
such
correlated
substituents;
direct
attack
on
kinetically
favored
most
systems,
rearrangements
become
competitive
with
leading
through
rearranged
carbocation
intermediates.
As
such,
reactions
depend
energies
access
their
corresponding
structures,
which
selectivity
guaranteed.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(11), P. 1805 - 1810
Published: March 15, 2023
We
report
an
operationally
simple
route
to
δ-valerolactones
through
organophosphorus-catalyzed
borylative
ring-opening/allylation
of
vinylcyclopropanes
providing
δ-hydroxy
esters
stereoselectively.
The
were
lactonized
obtain
densely
substituted
δ-valerolactones.
present
methodology
exhibited
enhanced
functional
group
tolerance
compared
the
existing
metal-mediated
methods.
A
plausible
mechanism
for
ring-opening
reaction
has
been
suggested.
31P
NMR
studies
indicated
involvement
a
phosphonium
zwitterionic
species.
synthetic
utility
intermediate
allyl
boronates
was
demonstrated.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(13), P. 2285 - 2288
Published: March 28, 2023
A
highly
efficient
SnCl4-catalyzed
nucleophilic
isocyanation
of
cyclopropyl
ethers
has
been
developed.
The
reaction
proceeds
at
the
quaternary
carbon
stereocenter
cyclopropane
with
a
complete
inversion
configuration,
providing
new
avenue
for
construction
synthetically
challenging
tertiary
alkyl
isonitriles
high
diastereopurity.
diversity
incorporated
isocyanide
group
demonstrated
by
transformation
into
corresponding
amines,
amides,
and
cyclic
ketoimines.
