Organic & Biomolecular Chemistry,
Год журнала:
2025,
Номер
23(10), С. 2400 - 2410
Опубликована: Янв. 1, 2025
In
this
study,
we
present
the
first
catalytic
methodology
for
synthesizing
N-methyl
secondary
amides
via
dehydrative
condensation
of
hydroxycarboxylic
acids
with
readily
available
and
safe
aqueous
methylamine,
employing
diboronic
acid
anhydride
(DBAA)
as
catalyst.
DBAA
catalysis
can
also
be
applied
to
direct
amidations
using
ethylamine
or
dimethylamine.
Moreover,
demonstrate
applicability
system
concise
synthesis
eight
biologically
active
compounds
containing
β-amino
alcohol
motifs,
including
halostachine,
synephrine,
longimammine,
phenylephrine,
metanephrine,
normacromerine,
etilefrine,
macromerine.
Bulletin of the Chemical Society of Japan,
Год журнала:
2020,
Номер
93(6), С. 759 - 767
Опубликована: Март 31, 2020
Abstract
An
account
of
the
development
Lewis-acid-catalyzed
methods
for
racemization-free
peptide
synthesis
is
presented.
These
are
based
on
substrate
control
concept
that
has
been
exploited
extensively
in
stereoselective
reactions,
but
never
previously
applied
to
synthesis.
The
most
important
difference
emerged
between
our
and
conventional
reagent
such
as
coupling-reagent-mediated
boronic-acid-catalyzed
bond-forming
reactions
how
activate
reaction
sites
racemization
control.
reagent-controlled
proceed
by
generating
highly
reactive
esters
situ,
leading
occasional
through
formation
oxazolone
intermediates.
On
other
hand,
substrate-controlled
do
not
go
known
processes
because
Lewis
acids
we
use
herein
designed
moderately
an
anchor
a
specific
carbonyl
group
located
at
reasonable
distance
from
directing
group.
Based
concept,
have
developed
six
novel
methodologies
over
last
five
years.
Organic Letters,
Год журнала:
2020,
Номер
22(21), С. 8658 - 8664
Опубликована: Окт. 12, 2020
We
report
the
catalytic
direct
peptide
bond
formations
via
dehydrative
condensation
of
β-hydroxy-α-amino
acids,
affording
serine,
threonine,
or
β-hydroxyvaline-derived
peptides
in
high
to
excellent
yields
with
functional
group
tolerance,
minimum
epimerization,
and
chemoselectivity.
The
key
success
these
atom-economical
transformations
is
use
diboronic
acid
anhydride
catalyst
for
hydroxy-directed
reactions.
Chemical Science,
Год журнала:
2021,
Номер
12(39), С. 12911 - 12917
Опубликована: Янв. 1, 2021
The
large
amount
of
waste
derived
from
coupling
reagents
is
a
serious
drawback
peptide
synthesis
green
chemistry
viewpoint.
To
overcome
this
issue,
we
report
an
electrochemical
in
biphasic
system.
Anodic
oxidation
triphenylphosphine
(Ph3P)
generates
phosphine
radical
cation,
which
serves
as
the
reagent
to
activate
carboxylic
acids,
and
produces
oxide
(Ph3P[double
bond,
length
m-dash]O)
stoichiometric
byproduct.
In
combination
with
soluble
tag-assisted
liquid-phase
synthesis,
selective
recovery
desired
peptides
Ph3P[double
m-dash]O
was
achieved.
Given
that
methods
reduce
Ph3P
have
been
reported,
could
be
recyclable
byproduct
unlike
byproducts
typical
reagents.
Moreover,
commercial
active
pharmaceutical
ingredient
(API),
leuprorelin,
successfully
synthesized
without
use
traditional
Chemical Communications,
Год журнала:
2021,
Номер
57(52), С. 6346 - 6359
Опубликована: Янв. 1, 2021
The
development
of
methods
for
amide
bond
formation
without
recourse
to
typical
condensation
reagents
has
become
an
emerging
research
area
and
been
actively
explored
in
the
past
quarter
century.
Organic Letters,
Год журнала:
2022,
Номер
24(5), С. 1175 - 1179
Опубликована: Янв. 27, 2022
Methyltrimethoxysilane
[MTM,
CH3Si(OMe)3]
has
been
demonstrated
to
be
an
effective,
inexpensive,
and
safe
reagent
for
the
direct
amidation
of
carboxylic
acids
with
amines.
Two
simple
workup
procedures
that
provide
pure
amide
product
without
need
further
purification
have
developed.
The
first
employs
aqueous
base-mediated
annihilation
MTM.
second
involves
crystallization
from
reaction
mixture
providing
a
low
process
mass
intensity
protocol.
Organic Letters,
Год журнала:
2023,
Номер
25(4), С. 694 - 697
Опубликована: Янв. 20, 2023
Diboron
substructures
have
emerged
as
a
promising
scaffold
for
the
catalytic
dehydrative
amidation
of
carboxylic
acids
and
amines.
This
Letter
describes
design,
synthesis,
evaluation
first
isolable
N(BOH)2
compound
an
catalyst.
The
new
catalyst
outperforms
previously
reported
B3NO2
heterocycle
catalyst,
with
respect
to
turnover
frequency,
albeit
former
gradually
decomposes
upon
exposure
work
opens
up
avenue
designing
better
direct
amidation.
Abstract
In
contrast
to
the
considerable
progress
in
development
of
methodologies
for
amide
bond
formation
amines,
direct
N
‐acylation
less
nucleophilic
‐heterocycles
and
amides
with
carboxylic
acids
is
still
challenging.
this
report,
we
describe
heterocycles
promoted
by
4‐(
,
‐dimethylamino)pyridine
‐oxide
(DMAPO)/di‐
tert
‐butyl
dicarbonate
(Boc
2
O)
system.
The
new
one‐pot
method,
which
does
not
involve
pre‐activation
substrates,
enables
a
wide
variety
nitrogen
nucleophiles
such
as
indole,
carbazole,
pyrrole,
pyrazole,
lactam,
oxazolidinone,
anilide
high
yield.
method
also
exhibits
excellent
functional
group
tolerance
broad
substrate
scope.
As
present
practical,
operationally
simple,
scalable,
it
should
find
applications
both
academic
industrial
laboratories.
The Chemical Record,
Год журнала:
2023,
Номер
23(5)
Опубликована: Март 30, 2023
Carbon-heteroatom
bond
formation
under
transition-metal
free
conditions
provides
a
powerful
synthetic
alternative
for
the
efficient
synthesis
of
valuable
molecules.
In
particular,
C-N
and
C-O
bonds
are
two
important
types
carbon-heteroatom
bonds.
Thus,
continuous
efforts
have
been
deployed
to
develop
novel
C-N/C-O
methodologies
involving
various
catalysts
or
promoters
TM-free
conditions,
which
enables
functional
molecules
comprising
in
facile
sustainable
manner.
Considering
significance
construction
organic
materials
science,
this
review
aims
comprehensively
present
selected
examples
on
(including
amination
amidation)
etherification
hydroxylation)
without
transition
metals.
Besides,
involved
promoters/catalysts,
substrate
scope,
potential
application
possible
reaction
mechanisms
also
systematically
discussed.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(14), С. 9853 - 9869
Опубликована: Июль 11, 2023
Triarylsilanols
have
been
reported
as
the
first
silicon-centered
molecular
catalysts
for
direct
amidation
of
carboxylic
acids
with
amines
identified
after
a
screen
silanols,
silanediols,
disiloxanediols,
and
incompletely
condensed
silsesquioxanes
potential
homogeneous
catalysts.
Subsequent
synthesis
testing
various
electronically
differentiated
triarylsilanols
tris(p-haloaryl)silanols
more
active
than
parent
triarylsilanol,
where
bromide
congener
is
found
to
be
most
active.
Catalyst
decomposition
can
observed
by
NMR
methods,
but
RPKA
methods
reveal
that
product
inhibition
operative,
tertiary
amides
are
inhibitory
secondary
amides.
Studies
using
an
authentically
synthesized
triaryl
silylester
putative
intermediate
in
catalytic
system
enable
plausible
mechanism
proposed
supported
computationals.
