Research Square (Research Square),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Feb. 1, 2023
Abstract
We
report
a
copper-catalyzed
ligand-controlled
selective
1,2-
and
1,4-hydrosilylation
of
1,3-enynes,
which
furnishes
enantiomerically
enriched
propargyl-
1,2-allenylsilane
products
in
high
yields
with
excellent
enantioselectivities
(up
to
99%
ee).
This
reaction
proceeds
under
mild
conditions,
shows
broad
substrate
scope
for
both
1,3-enynes
trihydrosilanes,
displays
regioselectivities.
Mechanistic
studies
based
on
deuterium-labeling
reactions
density
functional
theory
(DFT)
calculations
suggest
that
allenylcopper
is
the
dominant
reactive
intermediate
it
undergoes
metathesis
silanes
via
four-membered
or
six-membered
transition
state,
depending
nature
ligand.
The
weak
interactions
between
ligands
reacting
partners
are
found
be
key
controlling
factor
observed
regioselectivity
switch.
Chemical Communications,
Journal Year:
2023,
Volume and Issue:
59(49), P. 7483 - 7505
Published: Jan. 1, 2023
Copper-catalyzed
decarboxylative
reactions
are
powerful
strategies
for
the
construction
of
widely
available
skeletons
such
as
allenes,
ethynyl-containing
heterocycles,
and
quaternary
carbon
centers.
Accounts of Chemical Research,
Journal Year:
2024,
Volume and Issue:
57(5), P. 726 - 738
Published: Feb. 22, 2024
ConspectusBiologically
active
compounds
and
pharmaceutically
relevant
intermediates
often
feature
sterically
congested
stereogenic
centers,
in
particular,
carbon
stereocenters
that
are
either
tertiary
tetrasubstituted
ones
or
quaternary
nature.
Synthons
comprise
such
bulky
structurally
complex
core
units
of
high
synthetic
value
represent
important
incentives
for
communities
connected
to
drug
discovery
development.
Streamlined
approaches
give
access
a
diverse
set
incorporating
acyclic
relatively
limited,
though
vital.
They
enable
further
exploration
three-dimensional
entities
can
be
designed
implemented
programs,
thereby
extending
the
pool
molecular
properties
is
inaccessible
flat
molecules.
However,
lack
modular
substrates
particular
areas
chemical
space
inspired
us
consider
functionalized
heterocycles
known
as
cyclic
carbonates
carbamates
productive
way
create
crowded
alkenes
stereocenters.In
this
Account,
we
describe
major
approximations
followed
over
course
8
years
using
transition
metal
(TM)
catalysis
an
instrument
control
stereochemical
various
allylic
propargylic
substitution
processes
related
transformations.
Allylic
reactions
empowered
by
Pd-catalysis
utilizing
variety
nucleophiles
discussed,
with
amination
being
seed
all
combined
work.
These
procedures
build
on
vinyl-substituted
(VCCs)
simple
easy-to-access
precursors
highly
nature
compared
synthetically
limited
vinyl
oxiranes.
Overall
these
decarboxylative
conversions
take
place
"linear"
"branched"
regioselectivities
ligand
controlled
offer
wide
scope
functional
scaffolds.
Alternative
approaches,
including
dual
TM/photocatalyzed
transformations,
allowed
expand
repertoire
challenging
stereoselective
conversions.
This
was
achieved
through
key
single-electron
pathways
via
formal
umpolung
intermediates,
resulting
new
types
carbon–carbon
bond
formation
significantly
expanding
reactions.Heterocyclic
substrate
variants
have
triple
groups
were
also
difficult-to-promote
TM
catalysis.
In
processes,
Nishibayashi
laboratory
their
seminal
findings
area,
discovered
reactivity
patterns.
provided
range
different
stereodefined
building
blocks
1,2-diborylated
1,3-dienes
α-allenols
under
Cu-
Ni-catalysis.
realm,
use
lactone-derived
gives
elusive
chiral
γ-amino
acids
lactams
stereofidelity
good
structural
diversity.Apart
from
efforts,
elucidated
some
pertinent
mechanistic
manifolds
operative
transformations
better
understand
limitations
opportunities
specifically
synthons.
We
both
theoretical
experimental
investigations
lead
several
unexpected
outcomes
terms
enantioinduction
models,
catalyst
preactivation,
intimately
rationales
observed
selectivity
profiles.
The
work
communicated
offers
insight
into
unique
carbonates/carbamates
acting
privileged
precursors.
It
may
inspire
other
members
widen
toward
novel
added
development
academic
commercial
settings.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Aug. 19, 2023
We
report
a
copper-catalyzed
ligand-controlled
selective
1,2-
and
1,4-hydrosilylation
of
1,3-enynes,
which
furnishes
enantiomerically
enriched
propargyl-
1,2-allenylsilane
products
in
high
yields
with
excellent
enantioselectivities
(up
to
99%
ee).
This
reaction
proceeds
under
mild
conditions,
shows
broad
substrate
scope
for
both
1,3-enynes
trihydrosilanes,
displays
regioselectivities.
Mechanistic
studies
based
on
deuterium-labeling
reactions
density
functional
theory
(DFT)
calculations
suggest
that
allenylcopper
is
the
dominant
reactive
intermediate
it
undergoes
metathesis
silanes
via
four-membered
or
six-membered
transition
state,
depending
nature
ligand.
The
weak
interactions
between
ligands
reacting
partners
are
found
be
key
controlling
factor
observed
regioselectivity
switch.
origin
enantiocontrol
also
revealed
by
level
DLPNO-CCSD(T)
calculations.
The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
89(5), P. 2885 - 2894
Published: Feb. 14, 2024
Because
of
their
various
reactivities,
propargyl
acetates
are
refined
chemical
intermediates
that
extensively
applied
in
pharmaceutical
synthesis.
Currently,
reactions
between
and
chlorosilanes
may
be
the
most
effective
method
for
synthesizing
silylallenes.
Nevertheless,
owing
to
adaptability
selectivity
substrates,
transition
metal
catalysis
is
difficult
achieve.
Herein,
nickel-catalyzed
reductive
cross-coupling
substituted
vinyl
synthesis
tetrasubstituted
silylallenes
described.
Therein,
metallic
zinc
a
crucial
reductant
effectively
enables
two
electrophilic
reagents
selectively
construct
C(sp2)–Si
bonds.
Additionally,
Ni-catalyzed
mechanism
involving
radical
process
proposed
on
basis
deuteration-labeled
experiments.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(38)
Published: June 18, 2024
Described
herein
is
a
dirhodium(II)-catalyzed
silylation
of
propargyl
esters
with
hydrosilanes,
using
tertiary
amines
as
axial
ligands.
By
adopting
this
strategy,
range
versatile
and
useful
allenylsilanes
can
be
achieved
good
yields.
This
reaction
not
only
represents
S
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(39), P. 7263 - 7267
Published: Sept. 27, 2023
An
electroreductive
cross-coupling
of
prop-2-yn-1-yl
acetates
with
chloro(vinyl)silanes
for
producing
tetrasubstituted
silylallenes
is
developed.
The
method
enables
the
formation
a
new
C─Si
bond
through
cathodic
reduction
silyl
radical,
radical
addition
across
C≡C
bond,
alkenyl
anion
intermediate
formation,
and
deacetoxylation
represents
mild,
practical
route
to
synthesis
silylallenes.
Mechanistic
studies
reveal
that
CoCl2
acts
as
mediator
promote
via
electron
transfer.
The Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
87(18), P. 12019 - 12035
Published: Sept. 2, 2022
Efficient
palladium-catalyzed
vinylic
C-H
alkenylation
and
allenylation
of
gem-disubstituted
ethylenes
with
N-tosylhydrazones
aryl
alkyl
diaryl
ketones
were
achieved
to
access
trisubstituted
1,3-dienes
tetrasubstituted
allenes,
respectively.
An
vinyl
1,4-palladium
migration/carbene
insertion/β-hydride
elimination
sequence
proceeded
switch
the
chemo-
regioselectivities
give
structurally
diverse
products.
Use
2-FC6H4OH
additive
enables
enhancement
reaction
efficiency
through
accelerating
key
migration
process.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(4), P. 960 - 965
Published: Jan. 19, 2024
Divergent
transformations
of
allenylethylene
carbonates
with
diboron
reagents
catalyzed
by
copper
are
disclosed.
By
using
CuCl/IPr·HCl
as
the
catalyst,
react
B2hex2
to
afford
2,4-dien-1-ols
product
in
presence
Cs2CO3
base,
iPrOH
additive,
and
1,4-dioxane
solvent.
And
they
B2pin2
form
boronic
half
acids
NaOtBu
water
THF
The
reactions
corresponding
products
good
stereoselectivities
yields,
further
derivatizations
study
mechanism
also
demonstrated.
