Construction of 1,3‐Diboryl Allenes from gem‐Iododiboron Compounds via Intermolecular Boryl Group Transfer†
Chinese Journal of Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 23, 2025
Comprehensive
Summary
Allenylboronates
are
valuable
synthetic
building
blocks
and
have
garnered
significant
interest.
However,
their
1,3‐diboyl
substituted
analogs
not
been
reported.
Herein,
we
disclosed
a
novel
method
for
creating
allenes
from
gem
‐iododiboron
compounds
alkynyl
Grignard
reagents.
The
starting
materials
initially
converted
into
the
corresponding
propargylic
‐bis(boronates),
which
then
undergo
an
intermolecular
boryl
group
transfer
to
afford
allenes,
as
confirmed
by
mechanistic
studies.
This
features
good
tolerance
steric
hindrance
is
compatible
with
wide
variety
of
functional
groups.
Язык: Английский
Enantioselective Cobalt-Catalyzed Remote Hydroboration of Alkenylboronates
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 14, 2025
Heteroatomic
groups
in
alkenes
typically
direct
thermodynamically
favored
chain
walking
of
C═C
bonds
toward
themselves,
thereby
facilitating
C-H
bond
functionalization
near
the
heteroatoms.
We
present
herein
an
efficient
cobalt-catalyzed
contra-thermodynamic
remote
hydroboration
alkenylboronates
with
pinacolborane
to
synthesize
chiral
1,n-diboronates.
This
protocol
features
a
broad
substrate
scope,
high
functional
group
tolerance,
and
excellent
enantioselectivity.
Mechanistic
studies
indicate
involvement
chain-walking
process.
Gram-scale
reactions
various
product
derivatizations
further
highlight
its
practicality.
Язык: Английский
Synthesis of 1,2-Bis- and 1,1,2-Tris-Borylalkanes under Transition Metal-Free and Solvent-Free Conditions
The Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 19, 2025
Multi(boronate)
esters
are
useful
building
blocks
in
modern
chemical
synthesis.
Herein,
we
have
developed
an
efficient,
transition
metal-
and
solvent-free
method
for
the
regioselective
boration
of
alkenes
alkynes.
The
alkali
metal
Lewis
base
(NaOMe)-mediated
reactions,
using
bis(pinacolato)diboron
(B2pin2)
as
boron
reagent,
resulted
diboration
at
room
temperature
triboration
alkynes
60
°C
to
produce
synthetically
alkyl
1,2-bis(boronate)
1,1,2-tris(boronate)
esters,
respectively,
excellent
yields
with
high
regioselectivity.
This
environmentally
benign
protocol
demonstrates
a
broad
substrate
scope
good
functional
group
tolerance
gram-scale
reaction
further
highlights
practical
usefulness
method.
proposed
pathway
has
been
evaluated
based
on
stoichiometric
reactions
DFT
studies.
Язык: Английский
Zr-Catalyzed Assembly of 1,1,1-Triborylalkanes from Alkenes and HBpin
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 10, 2025
Multiboronated
compounds
play
more
and
significant
roles
in
the
chemical
community,
1,1,1-triborylalkanes
have
emerged
as
versatile
building
blocks
organic
synthesis.
However,
efficient
strategies
for
assembly
of
such
are
very
rare.
A
general
atom-economical
synthesis
from
various
alkenes
with
pinacolborane
(HBpin)
is
reported
first
time.
The
success
this
transformation
relies
on
use
commercially
available
Schwartz
reagent
(Cp2ZrHCl)
a
catalyst,
enabling
sequential
dehydrogenative
borylation
hydroboration.
This
reaction
demonstrates
excellent
selectivity,
high
yields,
broad
functional
group
tolerance.
Mechanistic
investigations
reveal
that
process
begins
two
consecutive
borylations
catalyzed
by
zirconium,
producing
1,1-diborylalkene
intermediate,
which
subsequently
undergoes
hydroboration
HBpin
to
afford
1,1,1-triborylalkanes.
Notably,
approach
allows
remote
1,1,1-triboration
internal
alkenes.
Язык: Английский