Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 2, 2025
We
recently
reported
a
chiral
phosphoric
acid
(CPA)
catalyzed
enantioselective
photomediated
ring
contraction
of
piperidines
and
other
saturated
heterocycles.
By
extruding
single
heteroatom
from
ring,
this
transformation
builds
desirable
C(sp3)–C(sp3)
bonds
in
the
contracted
products;
however,
origins
enantioselectivity
remain
poorly
understood.
In
work,
has
been
explored
across
an
expanded
structurally
diverse
substrate
scope,
revealing
wide
range
enantioselectivities
(0–99%)
using
two
distinct
CPA
catalysts.
Mechanistic
investigations
support
rate-determining
excitation
that
generates
short-lived
achiral
intermediates
are
intercepted
by
enantiodetermining
closure.
The
effects
competitive
uncatalyzed
reactivity
light-driven
reversibility
closure
on
have
elucidated.
Statistical
models
were
built
regressing
scope
against
key
structural
features
products
for
both
resultant
suggested
factors
influence
response
each
catalyst
enabled
rational
modification
pharmaceutically
relevant
target
molecule
to
improve
enantioselectivity.
Finally,
density
functional
theory
(DFT)-based
transition
state
analysis
identified
noncovalent
interactions
with
correlated
unique
selectivity-relevant
uncovered
through
statistical
modeling.
Our
findings
not
only
offer
comprehensive
insight
into
system
but
should
also
aid
future
development
related
CPA-catalyzed
reactions.
Organic Chemistry Frontiers,
Journal Year:
2024,
Volume and Issue:
11(7), P. 1924 - 1932
Published: Jan. 1, 2024
Amino
acid
formation
by
hydride
transfer
from
NADH
without
the
need
for
enzymes
connects
prebiotic
chemistry
with
metabolic
pathways
that
presumably
led
to
these
biomolecules
in
first
autotrophic
protocells.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(12), P. 4434 - 4451
Published: Jan. 1, 2024
This
study
incorporates
Minnesota
density
functionals
into
the
current
knowledge
of
describing
structural
and
dynamical
properties
liquid
water
through
ab
initio
molecular
dynamics,
with
M06-2X(-D3)
showing
most
promise.
Cell Reports Physical Science,
Journal Year:
2024,
Volume and Issue:
5(4), P. 101910 - 101910
Published: April 1, 2024
The
rise
of
polymeric
materials
marks
a
notable
achievement
the
past
century,
yet
challenges
in
recycling
have
led
to
their
accumulation
various
environments.
Efforts
address
this
include
advancements
mechanical
recycling,
degradation
processes,
and
chemical
techniques,
particularly
monomer,
which
offers
path
toward
circular
economy
for
plastics.
In
perspective,
we
discuss
how
ceiling
temperature
(Tc)
can
be
used
as
design
parameter
(closed-loop
recyclable)
polymers
provide
an
overview
typical
experimental
approaches
deriving
Tc,
focusing
on
ΔHp
ΔSp
key
parameters
prediction.
concept
Tc
is
heavily
embedded
polymer
literature
provides
simple
but
still
useful
way
quickly
ranking
different
terms
relative
thermodynamic
stability
versus
monomer
states.
While
bulk
state
intrinsic
value
desirable
quantity,
it
infeasible
many
cases
measure
equilibrium
states
bulk;
thus,
researchers
focused
investigating
solution,
where
there
may
dependencies
solvent,
concentration,
or
other
factors,
resulting
family
apparent
values
at
each
set
conditions.
We
thus
explore
computational
studies
complement
measurements
Tc.
To
end,
focus
here
advantages,
obstacles,
outlook
establishment
predictive
calculate
related
circularity,
namely
ΔHp,
ΔSp,
ΔGp,
values.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 2, 2025
We
recently
reported
a
chiral
phosphoric
acid
(CPA)
catalyzed
enantioselective
photomediated
ring
contraction
of
piperidines
and
other
saturated
heterocycles.
By
extruding
single
heteroatom
from
ring,
this
transformation
builds
desirable
C(sp3)–C(sp3)
bonds
in
the
contracted
products;
however,
origins
enantioselectivity
remain
poorly
understood.
In
work,
has
been
explored
across
an
expanded
structurally
diverse
substrate
scope,
revealing
wide
range
enantioselectivities
(0–99%)
using
two
distinct
CPA
catalysts.
Mechanistic
investigations
support
rate-determining
excitation
that
generates
short-lived
achiral
intermediates
are
intercepted
by
enantiodetermining
closure.
The
effects
competitive
uncatalyzed
reactivity
light-driven
reversibility
closure
on
have
elucidated.
Statistical
models
were
built
regressing
scope
against
key
structural
features
products
for
both
resultant
suggested
factors
influence
response
each
catalyst
enabled
rational
modification
pharmaceutically
relevant
target
molecule
to
improve
enantioselectivity.
Finally,
density
functional
theory
(DFT)-based
transition
state
analysis
identified
noncovalent
interactions
with
correlated
unique
selectivity-relevant
uncovered
through
statistical
modeling.
Our
findings
not
only
offer
comprehensive
insight
into
system
but
should
also
aid
future
development
related
CPA-catalyzed
reactions.
