ACS Organic & Inorganic Au,
Journal Year:
2022,
Volume and Issue:
2(6), P. 435 - 454
Published: Aug. 15, 2022
The
exploration
of
1,2-radical
shift
(RS)
mechanisms
in
photoinduced
organic
reactions
has
provided
efficient
routes
for
the
generation
important
radical
synthons
many
chemical
transformations.
In
this
Review,
basic
concepts
involved
traditional
1,2-spin-center
(SCS)
recently
reported
studies
are
discussed.
addition,
other
useful
1,2-RSs
addressed,
such
as
those
proceeding
through
1,2-group
migrations
carbohydrate
chemistry,
via
1,2-boron
shifts,
and
by
α-amino
radicals.
discussion
begins
with
a
general
overview
aspects
1,2-RS
mechanisms,
followed
demonstration
their
applicability
sections
that
follow
organized
according
to
operating
combination
migration
event.
This
contribution
is
not
comprehensive
review
but
rather
aims
provide
an
understanding
topic,
focused
on
more
recent
advances
field,
establishes
definition
nomenclature
been
used
describe
mechanisms.
ACS Catalysis,
Journal Year:
2022,
Volume and Issue:
12(15), P. 8911 - 8924
Published: July 11, 2022
Isomerizations
are
chemical
processes
where
a
compound
is
transformed
into
another
structure
while
retaining
the
same
formula.
When
dynamic,
these
reactions
amenable
to
convergent
synthetic
scenarios
one
isomer
reacts
preferentially
in
subsequent
step
or
accumulates
as
function
of
isomerization
mechanism.
With
recent
renaissance
photochemistry,
there
has
been
dramatic
increase
number
transformations
leveraging
radicals
and
diradicals
key
intermediates
for
isomerization.
This
perspective
will
examine
dynamic
approaches
isomerizations,
deracemizations,
kinetic
resolutions.
By
better
understanding
mechanisms
employ,
can
be
imagined
that
could
streamline
synthesis.
Nature Chemistry,
Journal Year:
2022,
Volume and Issue:
15(3), P. 424 - 435
Published: Dec. 30, 2022
Abstract
Site-selective
functionalization
is
a
core
synthetic
strategy
that
has
broad
implications
in
organic
synthesis.
Particularly,
exploiting
chiral
catalysis
to
control
site
selectivity
complex
carbohydrate
functionalizations
emerged
as
leading
method
unravel
unprecedented
routes
into
biologically
relevant
glycosides.
However,
robust
catalytic
systems
available
overcome
multiple
facets
of
stereoselectivity
challenges
this
end
still
remain
scarce.
Here
we
report
synergistic
Rh(I)-
and
organoboron-catalysed
protocol,
which
enables
access
synthetically
challenging
but
arylnaphthalene
Our
depicts
the
employment
Rh(I)
site-selective
showcases
utility
boronic
acid
compatible
co-catalyst.
Crucial
success
our
judicious
choice
suitable
organoboron
catalyst.
We
also
determine
exquisite
aspects
stereocontrol,
including
enantio-,
diastereo-,
regio-
anomeric
dynamic
kinetic
resolution,
are
concomitantly
operative.
The Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
88(9), P. 5713 - 5730
Published: April 20, 2023
The
use
of
quinuclidine
as
a
hydrogen
atom
transfer
(HAT)
mediator,
along
with
light-absorbing
photoredox
catalyst,
has
proved
to
be
powerful
and
general
approach
for
achieving
site-selective
radical
formation
from
carbohydrate
substrates.
Despite
numerous
literature
reports
documenting
the
scope
limitations
such
processes,
rationale
origins
site
selectivity
in
key
HAT
step
not
been
advanced.
In
this
study,
density
functional
theory
calculations
(M06-2X/def2-TZVP/PCM(acetonitrile))
were
used
model
transition
states
quinuclidinium
cation
pyranosides
furanosides
having
various
configurations
substitution
patterns.
data
set
(>120
state
geometries
energies)
allowed
detailed
examination
factors
that
influence
relative
rates,
augmented
by
additional
analysis
using
atoms
molecules
(AIM)
distortion/interaction-activation
strain
frameworks.
trends
have
emerged
regarding
effects
configuration,
conformation,
substitution,
noncovalent
interactions
are
consistent
experimental
observations
reveal
role
C-H···O
bonds
stabilizing
cation.
Chemical Communications,
Journal Year:
2021,
Volume and Issue:
57(91), P. 12135 - 12138
Published: Jan. 1, 2021
Site-selective
oxidations
of
carbohydrates,
employing
acridinium
photocatalysis
and
quinuclidine
hydrogen
atom
transfer
catalysis,
are
presented.
Protocols
have
been
developed
for
all-equatorial
carbohydrates
as
well
those
containing
cis-1,2-diols.
Site-selectivity
reflects
the
relative
rates
from
carbohydrate
C-H
bonds,
can
be
enhanced
using
a
phosphate
hydrogen-bonding
or
boronic
acid
catalyst.
ACS Organic & Inorganic Au,
Journal Year:
2022,
Volume and Issue:
2(6), P. 435 - 454
Published: Aug. 15, 2022
The
exploration
of
1,2-radical
shift
(RS)
mechanisms
in
photoinduced
organic
reactions
has
provided
efficient
routes
for
the
generation
important
radical
synthons
many
chemical
transformations.
In
this
Review,
basic
concepts
involved
traditional
1,2-spin-center
(SCS)
recently
reported
studies
are
discussed.
addition,
other
useful
1,2-RSs
addressed,
such
as
those
proceeding
through
1,2-group
migrations
carbohydrate
chemistry,
via
1,2-boron
shifts,
and
by
α-amino
radicals.
discussion
begins
with
a
general
overview
aspects
1,2-RS
mechanisms,
followed
demonstration
their
applicability
sections
that
follow
organized
according
to
operating
combination
migration
event.
This
contribution
is
not
comprehensive
review
but
rather
aims
provide
an
understanding
topic,
focused
on
more
recent
advances
field,
establishes
definition
nomenclature
been
used
describe
mechanisms.
