Journal of the American Chemical Society,
Journal Year:
2020,
Volume and Issue:
142(39), P. 16766 - 16775
Published: Sept. 4, 2020
Difunctionalization
reactions
of
C–C
σ-bonds
have
the
potential
to
streamline
access
molecules
that
would
otherwise
be
difficult
prepare.
However,
development
such
is
challenging
because
are
typically
unreactive.
Exploiting
high
ring-strain
energy
polycyclic
carbocycles
a
common
strategy
weaken
and
facilitate
reaction
σ-bonds,
but
there
limited
examples
highly
strained
being
used
in
difunctionalization
reactions.
We
demonstrate
bicyclo[1.1.0]butyl
boronate
complexes
(strain
ca.
65
kcal/mol),
which
were
prepared
by
reacting
boronic
esters
with
lithium,
react
electrophiles
achieve
diastereoselective
central
σ-bond
unit.
The
shows
broad
substrate
scope,
range
different
successfully
employed
form
diverse
set
1,1,3-trisubstituted
cyclobutanes
(>50
examples)
diastereoselectivity.
diastereoselectivity
observed
has
been
rationalized
based
on
combination
experimental
data
DFT
calculations,
suggests
separate
concerted
stepwise
mechanisms
operating,
depending
upon
migrating
substituent
electrophile
used.
Chemical Society Reviews,
Journal Year:
2019,
Volume and Issue:
48(13), P. 3464 - 3474
Published: Jan. 1, 2019
This
tutorial
review
describes
recent
developments
in
catalytic
reaction
design
that
involve
catalyst-promoted
1,2-metalate
shifts
as
a
critical
part
of
the
mechanism.
Chemical Reviews,
Journal Year:
2020,
Volume and Issue:
121(14), P. 8613 - 8684
Published: Nov. 2, 2020
Three-
and
four-membered
rings,
widespread
motifs
in
nature
medicinal
chemistry,
have
fascinated
chemists
ever
since
their
discovery.
However,
due
to
energetic
considerations,
small
rings
are
often
difficult
assemble.
In
this
regard,
homogeneous
gold
catalysis
has
emerged
as
a
powerful
tool
construct
these
highly
strained
carbocycles.
This
review
aims
provide
comprehensive
summary
of
all
the
major
advances
discoveries
made
gold-catalyzed
synthesis
cyclopropanes,
cyclopropenes,
cyclobutanes,
cyclobutenes,
corresponding
heterocyclic
or
heterosubstituted
analogs.
Chemical Communications,
Journal Year:
2020,
Volume and Issue:
56(43), P. 5718 - 5734
Published: Jan. 1, 2020
This
Feature
Article
provides
an
overview
of
research
advances
in
the
chemistry
spring-loaded
molecules,
focusing
mainly
on
strain-release
transformations.
Journal of the American Chemical Society,
Journal Year:
2019,
Volume and Issue:
141(24), P. 9511 - 9515
Published: May 29, 2019
While
radical
additions
to
π-bonds
are
well
established,
σ-bonds
far
less
explored.
We
have
found
that
electron
deficient
radicals
derived
from
alkyl
iodides
under
visible
light
irradiation
add
the
central
strained
bond
of
bicyclobutyl
(BCB)-boronate
complexes
and
lead
1,3-alkyl
disubstituted
cyclobutyl
boronic
esters
in
high
yields,
with
full
stereospecificity
levels
stereoselectivity.
Novel
cyclobutyl-substituted
structures,
including
peptide
steroid
ester
derivatives
can
be
accessed.
Additionally,
although
use
electron-rich
as
precursors
was
ineffective,
an
alternative
route
involving
alkylsulfonylation
BCB-boronate
followed
by
reductive
desulfonylation
provided
access
simple
substituted
cyclobutane
products.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
13(40), P. 11721 - 11737
Published: Jan. 1, 2022
A
flurry
of
reports
for
preparing,
functionalizing,
and
using
bicyclo[1.1.0]butanes
(BCBs)
have
positioned
them
to
be
powerful
synthons
with
numerous
applications.
This
review
discusses
the
recent
developments
regarding
this
strained
carbocycle.
Communications Chemistry,
Journal Year:
2023,
Volume and Issue:
6(1)
Published: Jan. 12, 2023
Abstract
Bicyclobutanes
are
among
the
most
highly
strained
isolable
organic
compounds
and
their
associated
low
activation
barriers
to
reactivity
make
them
intriguing
building-blocks
in
chemistry.
In
recent
years,
numerous
creative
synthetic
strategies
exploiting
heightened
have
been
presented
these
discoveries
often
gone
hand-in-hand
with
development
of
more
practical
routes
for
synthesis.
Their
proclivity
as
strain-release
reagents
through
weak
central
C–C
bond
has
harnessed
a
variety
addition,
rearrangement
insertion
reactions,
providing
rapid
access
rich
tapestry
complex
molecular
scaffolds.
This
review
will
provide
an
overview
different
options
available
bicyclobutane
synthesis,
main
classes
that
can
be
prepared
from
bicyclobutanes,
modes
used.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(27)
Published: April 20, 2022
The
development
of
two
divergent
and
complementary
Lewis
acid
catalyzed
additions
bicyclobutanes
to
imines
is
described.
Microscale
high-throughput
experimentation
was
integral
the
discovery
optimization
both
reactions.
N-arylimines
undergo
formal
(3+2)
cycloaddition
with
yield
azabicyclo[2.1.1]hexanes
in
a
single
step;
contrast,
N-alkylimines
an
addition/elimination
sequence
generate
cyclobutenyl
methanamine
products
high
diastereoselectivity.
These
new
contain
variety
synthetic
handles
for
further
elaboration,
including
many
functional
groups
relevant
pharmaceutical
synthesis.
reactivity
observed
attributed
differences
basicity
nucleophilicity
nitrogen
atom
common
carbocation
intermediate,
leading
either
nucleophilic
attack
(N-aryl)
or
E1
elimination
(N-alkyl).
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(51), P. 23685 - 23690
Published: Dec. 16, 2022
The
development
of
synthetic
strategies
for
the
preparation
bioisosteric
compounds
is
a
demanding
undertaking
in
medicinal
chemistry.
Numerous
have
been
developed
synthesis
bicyclo[1.1.1]pentanes
(BCPs),
bridge-substituted
BCPs,
and
bicyclo[2.1.1]hexanes.
However,
progress
on
bicyclo[3.1.1]heptanes,
which
serve
as
meta-substituted
arene
bioisosteres,
has
not
previously
explored.
Herein,
we
disclose
first
photoinduced
[3σ
+
2σ]
cycloaddition
trisubstituted
bicyclo[3.1.1]heptanes
using
bicyclo[1.1.0]butanes
cyclopropylamines.
This
transformation
only
uses
mild
operationally
simple
conditions
but
also
provides
unique
bioisosteres.
applicability
this
method
showcased
by
derivatization
reactions.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(22), P. 12324 - 12332
Published: May 26, 2023
Dearomative
photocycloadditions
are
valuable
chemical
transformations,
serving
as
an
efficient
platform
to
create
three-dimensional
molecular
complexity.
However,
the
photolability
of
original
addition
product
especially
within
context
ortho
cycloadditions
often
causes
undesired
consecutive
rearrangements,
rendering
these
cycloadducts
elusive.
Herein,
we
report
ortho-selective
intermolecular
photocycloaddition
bicyclic
aza-arenes
including
(iso)quinolines,
quinazolines,
and
quinoxalines
by
utilizing
a
strain-release
approach.
With
bicyclo[1.1.0]butanes
coupling
partners,
this
dearomative
[2π
+
2σ]
cycloaddition
enables
straightforward
construction
C(sp3)-rich
bicyclo[2.1.1]hexanes
directly
connected
N-heteroarenes.
Photophysical
experiments
DFT
calculations
revealed
origin
selectivity
indicate
that,
in
originally
proposed
energy
transfer
or
direct
excitation
pathways,
chain
reaction
mechanism
is
operative
depending
on
conditions.