With
the
advent
of
high-throughput
methods
for
both
computation
and
experimentation,
data-rich
approaches
to
discovering
understanding
chemical
reactions
are
becoming
ever
more
central
catalysis
research.
Organopalladium
is
at
forefront
these
new
approaches,
providing
a
rich
proving
ground
method
development
validation.
This
critical
Perspective
discusses
number
recent
case
studies
from
academic
industrial
laboratories
that
illustrate
how
generate,
analyze,
correlate
large
data
sets
quantitative
predictions
reactivity
selectivity.
Both
power
potential
pitfalls
discussed,
as
opportunities
practical
fundamental
mechanistic
insights.
ACS Central Science,
Journal Year:
2023,
Volume and Issue:
9(12), P. 2196 - 2204
Published: Dec. 8, 2023
Models
can
codify
our
understanding
of
chemical
reactivity
and
serve
a
useful
purpose
in
the
development
new
synthetic
processes
via,
for
example,
evaluating
hypothetical
reaction
conditions
or
silico
substrate
tolerance.
Perhaps
most
determining
factor
is
composition
training
data
whether
it
sufficient
to
train
model
that
make
accurate
predictions
over
full
domain
interest.
Here,
we
discuss
design
datasets
ways
are
conducive
data-driven
modeling,
emphasizing
idea
set
diversity
generalizability
rely
on
choice
molecular
representation.
We
additionally
experimental
constraints
associated
with
generating
common
types
chemistry
how
these
considerations
should
influence
dataset
building.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: July 3, 2023
High-throughput
experimentation
(HTE)
is
an
increasingly
important
tool
in
reaction
discovery.
While
the
hardware
for
running
HTE
chemical
laboratory
has
evolved
significantly
recent
years,
there
remains
a
need
software
solutions
to
navigate
data-rich
experiments.
Here
we
have
developed
phactor™,
that
facilitates
performance
and
analysis
of
laboratory.
phactor™
allows
experimentalists
rapidly
design
arrays
reactions
or
direct-to-biology
experiments
24,
96,
384,
1,536
wellplates.
Users
can
access
online
reagent
data,
such
as
inventory,
virtually
populate
wells
with
produce
instructions
perform
array
manually,
assistance
liquid
handling
robot.
After
completion
array,
analytical
results
be
uploaded
facile
evaluation,
guide
next
series
All
metadata,
are
stored
machine-readable
formats
readily
translatable
various
software.
We
also
demonstrate
use
discovery
several
chemistries,
including
identification
low
micromolar
inhibitor
SARS-CoV-2
main
protease.
Furthermore,
been
made
available
free
academic
24-
96-well
via
interface.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(14), P. 9755 - 9767
Published: March 26, 2024
Hydroxylated
(hetero)arenes
are
valued
in
many
industries
as
both
key
constituents
of
end
products
and
diversifiable
synthetic
building
blocks.
Accordingly,
the
development
reactions
that
complement
address
limitations
existing
methods
for
introduction
aromatic
hydroxyl
groups
is
an
important
goal.
To
this
end,
we
apply
base-catalyzed
halogen
transfer
(X-transfer)
to
enable
direct
C–H
hydroxylation
mildly
acidic
N-heteroarenes
benzenes.
This
protocol
employs
alkoxide
base
catalyze
X-transfer
from
sacrificial
2-halothiophene
oxidants
aryl
substrates,
forming
SNAr-active
intermediates
undergo
nucleophilic
hydroxylation.
Key
process
use
2-phenylethanol
inexpensive
hydroxide
surrogate
that,
after
substitution
rapid
elimination,
provides
hydroxylated
arene
styrene
byproduct.
Use
simple
2-halothiophenes
allows
6-membered
1,3-azole
derivatives,
while
a
rationally
designed
2-halobenzothiophene
oxidant
extends
scope
electron-deficient
benzene
substrates.
Mechanistic
studies
indicate
reversible,
suggesting
deprotonation,
halogenation,
steps
operate
synergy,
manifesting
unique
selectivity
trends
not
necessarily
dependent
on
most
position.
The
utility
method
further
demonstrated
through
streamlined
target
molecule
syntheses,
examples
regioselectivity
contrast
alternative
methods,
scalable
recycling
thiophene
oxidants.
Journal of Chemical Information and Modeling,
Journal Year:
2023,
Volume and Issue:
63(12), P. 3751 - 3760
Published: June 5, 2023
Fast
and
accurate
prospective
predictions
of
regioselectivity
can
significantly
reduce
the
time
resources
spent
on
unproductive
transformations
in
pharmaceutical
industry.
Density
functional
theory
(DFT)
reaction
modeling
through
transition
state
(TST)
machine
learning
(ML)
methods
has
been
widely
used
to
predict
outcomes
such
as
selectivity.
However,
TST
ML
are
either
time-consuming
or
data-dependent.
Herein,
we
introduce
a
prototype
seamlessly
bridging
by
triggering
resource-intensive
but
much
less
domain-sensitive
DFT
calculations
only
confident
predictions.
The
proposed
workflow
was
trained
tested
both
Pfizer
internal
dataset
USPTO
public
for
SNAr
reactions.
Our
method
is
fast,
which
achieves
96.3
94.7%
accuracy
predicting
correct
major
product
datasets,
respectively,
fraction
conventional
computing
time.
We
report
how
the
reaction
mechanism
and
site-selectivity
of
2-halopyridine
oxidative
addition
to
L2Pd(0)
are
both
controlled
by
frontier
molecular
orbital
symmetry.
Comparing
rates
for
pairs
2-chloro-3-EDG-pyridines
/
2-chloro-5-EDG-pyridines
(EDG
=
electron-donating
group:
NH2,
OMe
F)
Pd(PCy3)2
reveals
3-EDG
isomers
undergo
~100
times
faster
than
their
5-EDG
counterparts
(∆ΔG‡OA
10.4-11.6
kJ
mol-1).
Experimental
computational
mechanistic
studies
reveal
that
LUMO
symmetries
substrates
control
mechanism.
For
derivatives,
high
coefficients
at
reactive
C2
position,
antibonding
symmetry
through
C2=N
bond
pyridine
lead
a
nucleophilic
displacement
oxida-tive
Conversely,
derivatives
has
node
C5–C2
plane,
lead-ing
minimal
contribution
carbon.
The
higher
energy
LUMO+1
substantial
density
C2,
but
nitrogen.
This
leads
undergoing
3-centered
insertion
These
effects
also
multihalogenated
pyridines,
which
we
investigate
electron-withdrawing
substituents.
Incorporating
simple
fron-tier
based
descriptors
quantitative
multivariate
linear
model
im-proved
prediction
accuracy
relative
substituted
L2Pd(0).
We
report
how
the
reaction
mechanism
and
site-selectivity
of
2-halopyridine
oxidative
addition
to
L2Pd(0)
are
both
controlled
by
frontier
molecular
orbital
symmetry.
Comparing
rates
for
pairs
2-chloro-3-EDG-pyridines
/
2-chloro-5-EDG-pyridines
(EDG
=
electron-donating
group:
NH2,
OMe
F)
Pd(PCy3)2
reveals
3-EDG
isomers
undergo
~100
times
faster
than
their
5-EDG
counterparts
(∆ΔG‡OA
10.4-11.6
kJ
mol-1).
Experimental
computational
mechanistic
studies
reveal
that
LUMO
symmetries
substrates
control
mechanism.
For
derivatives,
high
coefficients
at
reactive
C2
position,
antibonding
symmetry
through
C2=N
bond
pyridine
lead
a
nucleophilic
displacement
oxida-tive
Conversely,
derivatives
has
node
C5–C2
plane,
lead-ing
minimal
contribution
carbon.
The
higher
energy
LUMO+1
substantial
density
C2,
but
nitrogen.
This
leads
undergoing
3-centered
insertion
These
effects
also
multihalogenated
pyridines,
which
we
investigate
electron-withdrawing
substituents.
Incorporating
simple
fron-tier
based
descriptors
quantitative
multivariate
linear
model
im-proved
prediction
accuracy
relative
substituted
L2Pd(0).