第3日講義資料

2013年度 化学専攻 特別講義3 有機典型元素化学特論@立教大学 第3回 8/7
1
担当:中央大学理工学部応用化学科 山下 誠
最先端有機元素化学:最新論文からのトピックス
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最先端有機元素化学①:最新論文からのトピックス
2
Phosphorus as a Lewis Acid: CO2 Sequestration with Amidophosphoranes
Lindsay J. Hounjet, Christopher B. Caputo, Douglas W. Stephan*
Angew. Chem. Int. Ed. 2012, 51, 4714.
CO2snapper: Compounds containing both acidic and basic
P,N functionalities have been prepared. Of these, two
amidophosphoranes containing highly reactive PN bonds
within four-membered rings react rapidly with CO2,
resulting in relief of ring strain. These compounds demonstrate
the utility of phosphorus as a Lewis acid for small-molecule
Prof. Stephan
University of Toronto
タイトルとTOCグラフィックから読み取れること
・リン原子がルイス酸になる
MOF: metal organic framework
・五配位のリン化合物(phosphorane)の話
Introductionから読み取れること
・二酸化炭素の話、特に貯留の話:例としてMOF, FLP
FLP: frustrated Lewis pair
北川進 (京都大学)
Omar Yaghi (UCLA)
Reviews:
Org. Biomol. Chem. 2008, 6, 1535
Dalton Trans. 2009, 3129
ACIE 2010, 49, 46.
Dow
studies
of
globalby reactivity,
from the
of 3(CO)
“frustrated
Sasaki andderived
co-workers,
whoconcept
used [Ru
introduction of CO2 into a solution of 1 in toluene at 100 8C
mix12]/KI Lewis
actor in
[12]
ious
and
pairs”, that is, systems in which steric congestion precludes produced the unique formatoborate complex [TMPH]n of H2
ave
been
zeolites,
neutralization.
These
[*] Dr. A. E. Ashley, Prof.
D. systems
O’Hare offer latent Lewis acidity and [HCO2B(C6F5)3] (2) in quantitative yield; the reaction can
in group
3
basicity
forResearch
reaction
with small
molecules.
In this vein, we[13] be monitored conveniently by solution 19F NMR spectroscowell as
Chemistry
Laboratory,
University
of Oxford
mperature
]
[14]
and
othersRoad,have
exploited
17),for
and the
Mansfield
Oxford
OX1 3TAthis
(UK)notion for the heterolytic py.[10] The 1H NMR (C7D8) spectrum of 2 revealed a downe
occuractivation
of dihydrogen and subsequent application of the field shift of the signals for the NH hydrogen atoms of about
An alterFax: (+ 44) 1865-272-690
2
mpounds
E-mail:
[email protected]
resulting
systems
in metal-free
catalytic hydrogenation and Reaction of FLP with H /CO
of
carbon
-workers
Reaction
of FLP
with
H
2
2
2
to [email protected]
to olefins.[15, 16] Herein, we demonstrate that the
strategies
Ge2 and
Dr. A. L. Thompson
Angewandte
tal-based
concept
of frustrated Lewis pairs can be exploited to effect
ree
sysChemie
Chemical
Crystallography,
for their
the
reversible
binding Inorganic
of carbonChemistry
dioxideLaboratory
under mild conum-based
ons. AlSouth Parks Road, Oxford OX1 3QR (UK)
ditions.
nation
of
hydride
2
[**] We A
thank
the EPSRC
for 6support,
Oxford
for covered
a Junior
solution
of B(C
F5)3 andBalliol
PtBuCollege,
orn and
1
3 in C6H
5Br was
hydride”
Research
(A.E.A.),
and Dr. Nick
Rees (CRL,
Oxford)
with
an Fellowship
atmosphere
of carbon
dioxide,
resulting
in for
the
tegies to
ounds to
NMR
support.
immediate precipitation of aScience
white 2006,
solid 314,
(1), which
xide is its
1124. was
Supporting
information
for
this
article
is
available
on
the
WWW
Scheme 2. Reversible reduction of CO2 to formate 2 with H2 activated
isolated in 87 % yield (Scheme 1). This product exhibited
reactivity.
niversity of
under http://dx.doi.org/10.1002/anie.200905466.
by a frustrated Lewis acid–base pair 1.
eact with
ed. E-mail:
Reaction
of FLP
ed transi-Fig. 1. Syntheses
of compounds
1 to 4. with CO2
! 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
9839
vert it toAngew. Chem. Int. Ed. 2009, 48, 9839 –9843
NOVEMBER
the
other 2006 VOL 314 SCIENCE www.sciencemag.org
p systems
into P!N,
e reports
GC analysis was pe
CH3, H) must occur (Scheme 4). This hypothesis was corrobenes.[9, 10]
diameter: 0.53 mm,
borated by the detection of H2O·B(C6F5)3 hydrogen-bonded
(hold, 2.5 min), th
were also
with various anions in the electrospray mass spectrum.[19]
Introduction: Frustrated Lewis Pair (FLP)
Communications
microanalyses were
politan University.
Received: Septemb
Published online: N
. Grimme,
HAN
.
Scheme 1. Reversible CO2 uptake and release by frustrated phosphine–
ACIE 2009, 48, 6643.
borane Lewis pairs.
31
1
11
1
resonances in the P{ H} and B{ H} NMR spectra at d = 46.1
and !2.7 ppm, respectively. The 19F NMR spectrum showed
signals at d = !133.5, !160.4, and !166.0 ppm, typical of C6F5
substituents on a four-coordinate boron center. The 13C NMR
spectrum of 1 showed resonances expected for the constituent
phosphorus and boron fragments as well as a signal at d =
Keywords: amine
methanol
Scheme 3. Proposed mechanism for the disproportionation of 2 into 4
and CO2.
ACIE 2009, 48, 9839.
Scheme
Thermolysis
[TMPH][HOB(C
)3] (3)oxygen
and [TMPH]6F5acyl
160
8C. 4.The
attack ofofB(C
F
)
on
the
atom of 2
6 5 3
[MeOB(C6F5)3] (4), and production of CH3OH.
produces an intermediate A (Scheme 3), which is thought to
give rise to the broad doublet observed at d = 174.5 ppm in
[1] a) http://www.c
Ruedy, M. Sato
S. Menon, T. N
Tausnev, Scien
[2] a) K. B. Lee, M
Chem. Res. 2
DOI: 10.1002/anie.201103600
arren E. Piers,* and Masood Parvez
CO
2 Reduction
, 2500 UniVersity DriVe NW, Calgary, Alberta, Canada T2N 1N4
Introduction
modified
FLP
Stoichiometric Reduction
of CO2 to2:CO
by Aluminum-Based
Reaction of FLP with H /CO
Reaction of CO with P/AlCl -FLP
of 2
Frustrated
Lewis
Pairs**
and NH ・BH (hydride equivalent)
afluo-
7, 2010; E-mail: [email protected]
Scheme 1
2
2
orm a
ethyld the
was
mhe
thedramatic rise in the consumption of fossil fuels since the
C(O)ndustrial
revolution has resulted in rapid increases in
quiv)
tmospheric
CO2 levels, exacerbating global climate
pidly
[1]
hange.
While mitigating emissions through reduced conerate
pidly
umption
and improved efficiency will most likely offer the
with
est
solutions, technologies such as carbon capture and
CO2
torage
t3SiH continue to be developed in the hopes of eliminating
is a industrial emissions.[2] In addition to the environmental
ome
ative
2
3
4
3
3
Gabriel M!nard and Douglas W. Stephan*
motivation, the rising costs and dwindling supplies of fossil
uels have prompted efforts to develop alternative energy
ources. While this has generated a number of clever
nnovations
in energy technology,[3–8] one approach that has
ic C1
such
arnered
attention and addresses both the environmental and
JACS 2010, 132, 10660.
urrent
lternative
energy
issues
is
based
on
the
concept of utilizing
es its
The ammonium hydridoborate ion pair 1 formed by treatment of
CO
fuels. Indeed, one perturbation of this10
ficient
2 as a Cthe
1 source
FLP B(Cfor
6F5)3/2,2,6,6-tetramethylpiperidine (TMP) and hydrogen
minant
mM, C6D5Br)economy”
reacted with CO
the presence
dea is the(32“methanol
espoused
byin Olah
someof
2 (2-4 atm)
of
[9, 10](18 equiv) at 56 °C to afford the previously reported7
Et3SiH
0er years
ago.
To avoid further environmental issues and
mple,
formatoborate 2 exclusively (see Scheme 1).11 The reaction was
eal
thermodynamic
this vision
requires versus
the
ductswith monitored
by 1H and 19realities,
F NMR spectroscopy,
and integration
[11, 12]
uctive
eduction an
ofinternal
CO2 standard
by photochemically
generated
H3SiH
(C6H5CF3, 9 mM) revealed
that no Et
2. was
7
ucing
consumed.
Thus,
the formation
of 2 is reversible,splitting
there does
While intense
efforts
arealthough
targeting
the photocatalytic
The species Mes3P(C(OAlI3)2 (1) was readily synthesized
JACS
2010,
132, 1796.analogues
in a similar fashion to chloride
and
bromide
[Eq. (1)].[16] The compound is isolated by precipitation after
Reaction of CO2 with P/AlI3-FLP to CO
ACIE 2011, 50, 8396.
5 minutes following the combination of the reagents. The
Al NMR resonance for 1 is observed at 20 ppm and is
27
spectively. However, in most cases the desired prod- gest that the phosphonium salt
uct was obtained in good to excellent yields but low bipyramidal configuration upon
diastereoselectivity. Higher reaction temperatures and Lewis base DMF. One of the
lower catalyst loading (2.5 mol%) had only a marginal oxygen atoms and the carbo
influence on the yield. The authors proposed that the occupy the 5apical positions,
reaction proceeds via the activation of the Lewis formed hypervalent bond.
Cyanohydrin trimethylsilyl e
basic imines by the coordination to the Lewis acidic
termediates, e.g., for the synthe
diphosphonium salt.
Recently Terada et al. reported about another fun- and b-amino alcohols.[39] The
damental carbon-carbon bond forming reaction that acetal as an aldehyde equivalen
can be catalyzed by phosphonium salts. They investi- dehyde dimethyl acetal, catalyz
gated the Diels–Alder reaction of a,b-unsaturated ported by Mukaiyama et al.[30]
amides and cyclopentadiene catalyzed by various the synthesis of cyanohydrin
phosphonium salts (Scheme 10).[26] The addition of from aldehydes and TMSCN ca
Tf2O increased the yield significantly. It was con- and easily accessible pho
firmed by control experiments that Tf2O alone did (Scheme 12).[40] Aliphatic, arom
not catalyze the reaction at all. In the presence of cat- aldehydes were converted unde
alyst 11, Z-configurated dienophiles gave the corre- yielding the corresponding cyan
ACIE 2010, 49, 5788.
2011, ethers
133, 18463.
sponding Diels–Alder product in excellentJACS
yields and
in good to excellent y
Thomas
Wernerthe e
REVIEW
high endo-selectivity (> 97%). In contrast, E-configu- a,b-unsaturated
aldehydes
rated amide dienophiles showed lower yields and a the desired product was obser
REVIEW
preference to form
the exo-products.
salt
The ability of the employed phosphonium salts to
[a] as a Lewis acid catalyst in this reaction
function
Table 1. Mukaiyama-aldol reaction.
strongly depended on the structure and the substituents at the phosphorus atom. A five-membered dioxaphosphacycle was thereby crucial for catalytic activity.
The performed coordination studies using 11 and
DMF as a model system revealed that DMF coordi-
Introduction 3: FLP other than Group 13/15
Group 14 Lewis Base
Phosphonium Salt Organocatalysis
Lewis酸としてのphosphonium
Scheme 2. Hypervalent interaction between a phosphonium
salt and a Lewis base.
Tetrahedron 2006, 62, 401.
Aldehyde
Nucleophile
Cat.
Scheme 10. Diels–Alder reaction catalyzed by 11.
the apical position of the trigonal bipyramidal ar8
rangement.[26,28]
Yield [%]
98[b]
This review covers the application of phosphonium
salts as Lewis acidic catalysts under homogeneous
conditions as well as the use of chiral derivatives as
asymmetric (phase-transfer) catalysts.
decreased with increasing steric demand of the sub- nates to the Lewis acidic organophosphorus com76 repound (Scheme 11). The performed NMR studies sugstituent R2 at the nitrogen and R6 at7 the silicon,
spectively. However, in most cases the desired prod- gest that the phosphonium salt arranged in a trigonal
bipyramidal configuration upon coordination of the
uct was obtained in good to excellent7 yields but
67 low
diastereoselectivity. Higher reaction temperatures and Lewis base DMF. One of the two catechol moiety
lower catalyst loading (2.5 mol%) had only a marginal oxygen atoms and the carbonyl oxygen of DMF
11. Formation and coordination mode of the DMF/
Scheme 12. Cyanosilylation of alde
2 C!C Bond Forming Reactions
occupy the apical positions,
thus stabilizing the
influence on the yield. TheScheme
authors
proposed
that
7
54 the
phosphonium salt 11 complex.
and selected examples.
reaction proceeds via the activation of the Lewis formed hypervalent bond.
In the course of their investigations to explore novel basic imines by the coordination to the Lewis acidic
Cyanohydrin trimethylsilyl ethers are versatile in1474
asc.wiley-vch.de
! 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
metal-free Lewis acidic catalysts Mukaiyama et al. in- diphosphonium salt.
termediates,
e.g., for the synthesis of a-hydroxy acidsAdv. Sy
7
53
vestigated the use of phosphonium salts as catalysts in Recently Terada et al. reported about another fun- and b-amino alcohols.[39] The cyanosilylation of an
several carbon-carbon bond forming reactions.[29,30] damental carbon-carbon bond forming reaction that acetal as an aldehyde equivalent, namely E-cinnamalJACS
2008, 130,salts
10890.
They successfully employed
diphosphonium
7 can be catalyzed by phosphonium salts. They investi- dehyde dimethyl acetal, catalyzed by 7 was first reand 8 as a catalyst in Mukaiyama-aldol reactions of gated the Diels–Alder reaction of a,b-unsaturated
ported by Mukaiyama et al.[30] Plumet et al. reported
7
71[c]
aldehydes with silyl enol ethers and ketene silyl ace- amides and cyclopentadiene catalyzed by various the synthesis of cyanohydrin trimethylsilyl ethers
tals (Table 1). In all cases, the reactions proceeded phosphonium salts (Scheme 10).[26] The addition of from aldehydes and TMSCN catalyzed by the simple
この論文を読む上での
→
wis Acid: CO2 Sequestration with
s**
This Work 1: Synthesis of Amidophosphorane
of ring-strained
amidophosphorane
opher B.Synthesis
Caputo,
and Douglas
W. Stephan*
and its reaction with CO2
6
no reaction
δH 4.68 (br q, 1JHH = 5 Hz)
13CO /CD Cl
2
2 2
gas has prompted widee. To date, a number of
sequester this gasNHusing XeF2
PPh2
zeolites, activated carbon,
δ 94.4
(d, J = 980 Hz)
MOFs).[1] While some of
δ −45.6
increasing scale, efforts to
(t, J = 625 Hz)
rategies for CO2 capture
1) Nの脱プロトン
δ 2.28 (dd, J = 4.4 Hz,
δ 3.15 (s)
J = 2.4 Hz)
2) Pへ求核攻撃
of metal-free, frustrated
(n-BuLi, NEt3
ecent attention.[2] In 2009,
ではダメだった)
ing of CO2 by borane/
δ 153.1 (d, J = 8 Hz)
nt work by the groups of
ν = 1696 cm
selves,[6] has demonstrated
黄色
参考:5配位三方両錐構造
ap
d FLPs for the conversion
δ −57.0
eq ap: apical
(d, J = 664 Hz)
eq
E
CO.
eq: equatorial
δ −44.6
eq
Scheme
1.
Synthesis
(d, J = 679 of
Hz)2–4.
ap
d/base combinations
conP chemistry, less attention
variety of FLP systems
m the original systems has
methyl signal at d = 2.67 ppm. With the amine functionality
P
P
4
H
1
3
PH
H
FH
CO
P
[7]
1
PF
PF
C
P
1
PF
!
1
PF
1
PC
−1
the 31P{1H} spectrum shows a doublet at d = !57.0 ppm, with
JPF = 664 Hz. The corresponding 19F NMR signal is seen at
d = !34.2 ppm. IR data for 4 show a characteristic carbonyl
absorption band at 1696 cm!1. Collectively, these data suggest
that 4 is the carbamatofluorophosphorane Ph2PF(oC6H4N(Me)CO2), and this formulation was confirmed by Xray crystallography (Figure 2).[12] Insertion of CO2 into the
Angewandte ring with
activated P!N bond of 3 results in a six-membered
Chemie
1
This Work 2: Crystal Structure of 3 and 4
Crystal Structure of 3
Scheme 2. Synthesis of 6–8.
7
phorane PhPF2(o-C6H4NHMe)2 (5), an
ion abstraction by Me3SiO3SCF3 gener
C6H4NMeH)2][O3SCF3] (6). The spect
compounds closely matched those
derivatives. Crystallographic data of 6
lation and revealed P···N separations
estingly, both amine H atoms are
suggesting hydrogen bonding, althoug
of about 2.4 ! indicate that this i
Consistent with the reactivity describ
of 2 equiv of tBuLi to 5 resulted in the
PhP(o-C6H4NMe)2 (7), which was isola
75 % yield. The 31P{1H} NMR spectru
nucleus with a singlet at d = !58.7 p
spectrum demonstrates the C2 mole
a single NMe resonance at d = 2.55 p
Treatment of 7 with 1 atm of CO2 und
an elongated P!O bond (1.775(1) ! and 1.778(1) !) in each
of two molecules in the asymmetric unit. Within 4, the
geometry about P is trigonal bipyramidal with the carbamato
O occupying an axial position trans to F. The C!O and C=O
bonds in the CO2 fragment of 4 average 1.330(2) and
1.212(2) !, respectively, which are slightly longer than those
seen in tBu3PCO2B(C6F5)3 (1.299(2) !, 1.208(2) !)
and
(Me3C6H2)2PCH2CH2B(C6F5)2(CO2)
(1.284(4) !,
1.209(4) !). Compounds 3 and 4 are both rare examples of
crystallographically characterized phosphoranes, and to the
best of our knowledge, 4 is also the first known pentacoordinate phosphorane containing a carbamato substituent.
Figure 1. POV-ray depiction of 3.
Although kinetically Figure
hindered
insertion
CO2 into the
2. POV-ray
depictionof
of 4.
P!N bond of (CF3)3PMe(NMe2) has been previously reported
two crystallographically independent molecules to proceed over several
Angew. Chem.
Ed. 2012,
–4717
! 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
daysInt. to
give51, a4714six-coordinate
=
zwitterionic carbamatophosphate,[13] the facile insertion of
crystallographically independent molecules. The N atom
occupies an axial position opposite F, although the N!P!F
CO2 into the P!N bond of 3, relieves strain within the fourangles (164.4(3)8 and 165.1(3)8) are somewhat distorted from
membered ring, thereby dramatically accelerating the reac結合3本による角度の和が360°
tion. It is noteworthy that 4 is thermally robust, as itFis
linearity, presumably
in response to constraints imposed by
unchanged on heating to 120 8C in toluene for 1 h.
the equatorially disposed
anilido Cipso. The geometry of the
=
amido unit is nearly
planar,
as
the
sum
of
the
angles
about
N
is
Related compounds incorporating a second o-N-methylsum of angles around N = 356°
C
3568 and the N!Cortho distances of 1.439(9) ! and 1.442(10) !
aniline group were prepared (Scheme 2). Oxidative fluorinaPh
P
1.439(9)
Å
C−N結合は
tion of PhP(o-C6H4NHMe)2 with XeF2 produced the phosare typical of single bonds. The C!C bonds within the anilido
Me
通常の長さ
1.442(10)
Å in
ring are similar to those within neighboring
Ph rings,
Ph
contrast to1.842(7)
the dearomatization
observed
within
metal
comÅ
N
O 1.775(1) Å
plexes of the amidophosphine ligand.[14]
1.839(6)
Å
N
The exposure of a bright-yellow THF solution of 3 to
1.778(1) Å
Phtemperature results in its immediate
C
1 atm of CO2 at ambient
Me
C–O av. 1.330(2) Å
discoloration, and NMR analysis
P performed
C shortly thereafter indicates complete conversion to a new species (4). The
O C=O av. 1.212(2) Å
1
H NMR spectrum Ph
of 4 shows a singlet N-methyl resonance at
164.4(3)°
d = 3.15 ppm, and the loss of its coupling
to both P and F is
!
165.1(3)°
consistent with rupture of the
P
N
bond
within 3 to
F
accommodate CO2. The 13C{1H} NMR spectrum shows the
B(C6F5)2
X線で得られる結合距離・角度は
CO2 unit as a doublet at d = 153.1 ppm with 2JPC = 8 Hz, while
O B(C6F5)3
the 31P{1H} spectrum shows a doublet at d = !57.0 ppm, with
末尾の桁の後ろに括弧書きで
O
tBu P C
1
JPF = 664 Hz. The corresponding 19F NMR signal is seen at
C–O av. 1.299(2) Å Mes P C C–O av. 1.284(4) Å
3
標準偏差が記されている
3
C=O av. 1.209(4) Å
d = !34.2 ppm. IR data for 4 show a characteristic carbonyl
O C=O av. 1.208(2) Å
O
!1
absorption band at 1696 cm . Collectively, these data suggest
Scheme 2. Synthesis of 6–8.
that 4 is the carbamatofluorophosphorane Ph2PF(oC6H4N(Me)CO2), and this formulation was confirmed by X-
unchanged on heating to 120 8C in toluene for 1 h.
nilido Cipso. The geometry of the
as the sum of the angles about N is
Related compounds incorporating a second o-N-methylaniline group were prepared (Scheme 2). Oxidative fluorinaces of 1.439(9) ! and 1.442(10) !
8
tion of PhP(o-C6H4NHMe)2 with XeF2 produced the phos- 2
The C!C bonds within the anilido
within neighboring Ph rings, in
.
Angewandte
Communications
tion observed within metal comne ligand.[14]
instantly produced PhP(o-C H N(Me)CO ) (8), which was
isolated in 80 % yield. The P{ H} NMR spectrum of 8
NH
ht-yellow THF solution
ofN 3 XeF
to 2
showed a single peak at d = !68.6 ppm, and the loss of J ,
which was made evident by the singlet NCH signal in the
mperature results in itsPPh
immediate
2 H
H NMR spectrum, was consistent with CO insertion into
nalysis performed shortly thereeach of the chemically equivalent P!N bonds. The H and
C{ H} NMR data were also consistent with the formulation
nversion to a new species (4). The
of 8 as the double insertion product. Use of CO revealed
ws a singlet N-methyl resonance at
a strong signal at d = 152.8 ppm in the C{ H} NMR spectrum
and IR spectroscopy of 8 showed the expected carbonyl
of its coupling to both P and F is
absorption at 1697 cm .
The formulation of 8 was also confirmed by its X-ray
f the P!N bond within 3 to
structure (Figure 3), which showed the pseudo-C -symmet1
C{ H} NMR spectrum shows theδ −58.7 (s)
ric geometry of the dicarbamatophosphorane, wherein
P
2
153.1 ppm with JPC = 8 Hz, while
a doublet at d = !57.0 ppm, with
nding 19F NMR signal is seen at
4 show a characteristic carbonyl
!1
δH 2.55 (d, 3JPH = 6.8 Hz)
. Collectively, these data suggest
δP −68.6 (s)
Scheme 2. Synthesis of 6–8.
atofluorophosphorane Ph2PF(oδC 152.8 (d, 1JPC = 8 Hz)
ormulation was confirmed by XνCO = 1697 cm−1
[12]
2). Insertion of CO2 into the
sults in a six-membered ring with
phorane PhPF2(o-C6H4NHMe)2 (5), and subsequent fluoride
ion abstraction by Me3SiO3SCF3 generated the salt [PhPF(oC6H4NMeH)2][O3SCF3] (6). The spectral parameters of these
compounds closely matched those of their monoaniline
Figure1.7635(8),
3. POV-ray depiction
of 8.
PーO:
1.7773(8)
Å
derivatives. Crystallographic data of 6 confirmed the
formuOーPーO: 174.27(4)°
lation and revealed P···N separations of 3.05–3.12
!. Inter直線に近いアピカル結合
oxygen donors occupy both axial positions, while the C
estingly, both amine H atoms are oriented
atoms of F,
the aryl groups lie in the equatorial plane. The
= towards
lengths of mutually trans P!O bonds were found to be
suggesting hydrogen bonding, although the H···F separations
1.7635(8) and 1.7773(8) !, with an O!P!O angle of
[15]
174.27(4)8. The C!O and C=O bonds in 8 average 1.339(1)
of about 2.4 ! indicate that this interaction is weak.
This Work 3: Double Insertion of CO
6
4
31
2 2
1
3
3
1
13
PH
a possib
3 (Schem
tion in
2
1
1
13
13
1
2
!1
[12]
Scheme 3
2
amido d
reminisc
develop
insertion
reported
HC(NR
molecul
In su
four-me
equivale
substrat
These fi
capabili
PV Lewi
efforts w
Received
Published
.
Keyword
Lewis ac
ipso
[1] a) A
O. M
Row
Scie
instantly produced PhP(o-C6H4N(Me)CO2)2 (8), which was
isolated in 80 % yield. The 31P{1H} NMR spectrum of 8
uto,
and Douglas
W. Stephan*
showed a single
peak at d = !68.6 ppm, and the loss of 3JPH,
Stephan*
which was made evident by the singlet NCH3 signal in the
1
H NMR spectrum, was consistent with CO2 insertion into
d wideeach of the chemically equivalent P!N bonds. The 1H and
13
mber of
C{1H} NMR data were also consistent with the formulation
as using
of 8 as the double insertion product. Use of 13CO2 revealed
a strong signal at d = 152.8 ppm in the 13C{1H} NMR spectrum
carbon,
and IR spectroscopy of 8 showed the expected carbonyl
ome of
absorption at 1697 cm!1.
fforts to
The formulation of 8 was also confirmed by its X-ray
capture
structure (Figure 3),[12] which showed the pseudo-C2-symmetustrated
ric geometry of the dicarbamatophosphorane, wherein
In 2009,
borane/
oups of
nstrated
nversion
a possibility, it is also noteworthy that the resonance forms of
3 (Scheme 3) suggest the possibility of an FLP-type description in which a charge-separated P!N bond consists of an
Consideration about FLP Reactivity
CO2
Scheme 3. Resonance forms of 3.
It can be considered that 3 is in resonance
with ring-opening and charge-separated form
amido donor and a phosphonium acceptor. This view of 3 is
reminiscent of a B/P FLP, (C6H2Me3)2PCH2CH2B(C6F5)2,
developed by Erker and co-workers.[16] In this regard, the CO2
4
insertion
chemistry discussedshowed
herein is FLP
also analogous
amidophosphorane
property to that
reported for the four-membered rings of boron imidinates,
Cf.
HC(NR)2B(C6F5)2, which are also thought to react with small
molecules via an open FLP form.[17]
Scheme 1. Synthesis of 2–4.
In summary, amidophosphoranes 3 and 7, containing the
ns
consis of
2–4.
four-membered rings, react rapidly to capture of one and two
ttention
132, 13559.
equivalents of CO2, respectively.JACS
These2010,
compounds
bind the
systems
substrate in a manner analogous to related FLP systems.
ems has
methyl signal at d = 2.67 ppm. With the amine functionality
These findings have prompted further study of the acceptor
at d = 2.67 ppm. With the amine functionality !
of electron-poor phosphonium cations to provide
unaffected by fluorination, facile F abstraction from capabilities
at work,
1 by
fluorination, facile F! abstraction from 1 by
V
P
Lewis
acid
centers for FLP chemistry. The results of these
d Lewis
Me3SiO3SCF3 yields [Ph2PF(o-C6H4NHMe)][O3SCF3] (2),
yields [Ph2PF(o-C
H
NHMe)][O
SCF
]
(2),
6 4
3
3
efforts will be reported in due course.
What can we do next?......
as been
a rare example of a compound containing both acidic
le of a compound containing both acidic
phosphonium and pendant amine functionalities. Received:
The February 20, 2012
Group 4
and pendant
functionalities. The
31
1 amine
Published
variety
P{ H} NMR spectrum of 2 reveals a strongly deshielded
P online: April 4, 2012
spectrum of 2 reveals a strongly deshielded P
1
hes, we
nucleus with a doublet
resonance at d = 94.4 ( JPF = 980 Hz),
doublet resonance
d1 = 94.4
(1JPFof =
980 Hz),
Figure 3.atPOV-ray
depiction
amidophosphoranes · carbon dioxide ·
ons and
while the H spectrum8. is largely unchanged, exceptKeywords:
for
Lewis acids and bases · phosphonium · pnictogens
spectrum is largely unchanged, except for
hosphoa downfield shift of the NH signal to d = 5.20.
ift of the NH signal to d = 5.20.
The combination
of
unquenched
Lewis acidic and basic
s in FLP
oxygen donors
occupy
both
axial
positions, while the Cipso
nation of unquenched
Lewis
acidic
and
basic
pnictogens
within
2 prompted
our investigation of its
nophosatoms of
the
aryl groups
lie in
thin 2 prompted
our
investigation
of the
itsequatorial plane. The
.
9
現代化学における情報戦①:ChemDrawを使いこなせ
ChemDrawショートカット
例:酸素を書く
Oをタイプ
Oをタイプ
Oをタイプ
自動的に水素原子を補完
http://pute.seesaa.net/article/152301606.html
http://pute.seesaa.net/article/152727364.html
http://d.hatena.ne.jp/gyrase/20120303
化学ポータルサイトChem-Station紹介記事
http://www.chem-station.com/blog/2012/12/post-466.html
10
最先端有機元素化学②:最新論文からのトピックス
11
Coplanar Oligo(p-phenylenedisilenylene)s Based on the Octaethyl-Substituted s-Hydrindacenyl Groups
Fukazawa, A.; Li, Y.; Yamaguchi, S.; Tsuji, H.; Tamao, K.
J. Am. Chem. Soc. 2007, 129, 14164. The silicon analogues of the oligo(p-phenylenevinylene)s (Si-OPVs) with highly
planar structures have been synthesized using a newly developed ligand, the
1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl (Eind) group. Their X-ray crystal
structures and spectroscopic data demonstrate that the π-conjugation effectively
extends over the Si-OPV framework. Notably, tetrasiladistyrylbenzene exhibits an
orange fluorescence even at room temperature both in solution and in the solid
state, which is attributable to the effective extension of conjugation. To the best of
our knowledge, the tetrasiladistyrylbenzene is the first emissive Si=Si derivative
even at room temperature.
タイトルとTOCグラフィックから読み取れること
・OPV[oligo-(p-phenylenevinylene)]のケイ素誘導体の話
Si=Si二重結合がベンゼンを挟んでいる
・Eind基という配位子が新しく合成された
玉尾皓平
勇人
深澤愛子
京都大学名誉教授 東京大学准教授 名古屋大学准教授
・この化合物は溶液状態・固体状態でオレンジの蛍光を発する
Introductionから読み取れること
・Si=C,P=P,Si=Siなどの重い二重結合は
・P=C, P=P, Si=Si, Ge=C, Ge=Geのオリゴマーやポリマーが合成されたが
Oligomer and Polymer of Heavy Double Bond
P=C polymer
JACS 2006, 128, 8836.
ACIE 2002, 41, 2389.
P=P polymer
Inorg. Chem. 2003, 42, 5468.
JACS 2004, 126, 2268.
12
Oligomers of Group 14 Double Bonds
Conjugated Si=Si bonds
Conjugated Ge=C, Ge-Ge bond
Organometallics 2000, 19, 2835.
ACIE 1997, 36, 2503.
Organometallics 2004, 23, 3088.
ACIE 2000, 39, 3703.
ACIE 2007, 46, 5783.
13
This Work 1: Synthesis of Dibromosilane 3
Synthesis of Eind-Br
Synthesis of 3
14
This Work 2: Synthesis of Disilene and Bis(disilene)
Synthesis of bis(dibromosilane) 4
Synthesis of disilene 1 and bis(disilene) 2
Stable solid!
15
This Work 3: Crystal Structure of 2
Crystal Structure of 2
真ん中のベンゼン環の中心にC2対称軸が存在
=
SiーSi 2.156(2) Å
SiーC 1.860(6); 1.876(6); 1.911(5); 1.902(5) Å
Si周りの結合角の和=両方360°
16
This Work 4: Photophysical Properties of 2
1 vs 2:
5 vs 2:
7 vs 2, 6 vs 1:
Tip
Si
Tip Si
Tip
5
Eind
Eind
Si Ph Eind
Si Ph
Ph Si
Si
Si
Eind Ph Si
Eind
1
Eind 2
H
Tip
H
H
Si Tip
C Ph
C Ph
C
C
Si
Ph C
Ph C
H
Tip
H
H
6
7
Figure S4. Electronic spectra of Si-OPVs 1 and 2
in n-hexane at ambient temperature.
参考:蛍光発光のメカニズム
UV-vis absorption of 1 (gray) and 2 (black solid line)
(Jablonski図)
luminescence spectrum of 2 (black dotted line, excited at 460 nm)
excitation spectrum of 2 (black broken line, observed at 620 nm)
luminescence spectrum:
excitation spectrum:
17
This Work 5: Luminescence and MOs
18
Figure S5. Photographs of compound 2.
(a) solid in sealed tube in the dark
(b) solid under irradiation at 254 nm
(c) solution in hexane under irradiation at 254 nm
計算レベルはB3LYP/6-31G(d)
What can we do next?......
現代化学における情報戦②:webを最大限活用せよ
参考文献の探し方
19
Elsevier
1. 元の論文のURLがわかっている場合
その論文の引用文献にリンクが張ってある場合が多い
ACS
Wiley
RSC
各参考文献へのリンクが羅列されているところで
Ctrlキーやappleキーを押しながらリンクをクリックしていくと、タブが連続して開く
2. 元の論文のURLがわからない場合
参考:山下研website: http://www.chem.chuo-u.ac.jp/~element/
2-1. Article LocatorやOrganic Chemistry reference resolverを使う
このあたりに参考文献書式をコピー&ペーストして
searchボタンをクリック(J. Am. Chem. Soc. 1996, 118, 7004.)
それぞれオリジナルのwebsiteをbookmarkしても良い
http://alocator.web.fc2.com/
http://chemsearch.kovsky.net/
化学ポータルサイトChem-Stationにも紹介記事あり
http://www.chem-station.com/blog/2011/02/-chemistry-reference-resolver.html
http://www.chem-station.com/blog/2011/02/post-243.html
http://www.chem-station.com/blog/2011/02/-firefox.html
2-2. DOI (digital object identifier)を使う
現在発行されている全ての論文にはdoiという
固有の文字列が与えられている
(書式: 雑誌を表す数字/論文番号, 例: 10.1021/ja9100276)
http://www.doi.org/ へアクセスし、論文に記載されているdoiを入力
自動的に該当する論文のウェブページへ移動できる
なお、ページ番号が決定する前後でdoiは不変(=ASAP時点で登録も可能)
最先端有機元素化学③:最新論文からのトピックス
20
Iodomesitylene-Catalyzed Oxidative Cleavage of Carbon−Carbon Double and Triple Bonds
Using m-Chloroperbenzoic Acid as a Terminal Oxidant
Miyamoto, K.; Sei, Y.; Yamaguchi, K.; Ochiai, M.
J. Am. Chem. Soc. 2009, 131, 1382-1383.
Transition metal-catalyzed oxidative cleavage of carbon−carbon multiple bonds
has emerged as a powerful tool in organic synthesis. High-valent oxometals,
mostly of Ru, Os, Mn, Mo, W, and Re, were used catalytically as reactive oxygen
transfer agents to the multiple bonds. Reported here for the first time are the
organocatalytic versions of the oxidative cleavage reactions. Our method involves
use of iodomesitylene as an effective organocatalyst, which generates an active
aryl(hydroxy)-λ3-iodane 5 in situ, and m-chloroperbenzoic acid (m-CPBA) as a
terminal oxidant under metal-free conditions. Cyclic and acyclic olefins as well as
aliphatic and aromatic alkynes were smoothly cleaved to carboxylic acids under
the organocatalytic conditions.
タイトルとTOCグラフィックから読み取れること
・アルケンやアルキンのC-C結合を切断してカルボン酸にできる
・触媒はヨードメシチレンで酸化剤がmCPBA
TOCから読み取れること
・遷移金属、特に高原子価金属オキソ錯体での
・酸化的切断の
・
はmCPBAにより
落合正仁
徳島大学教授
Oxidative Cleavage of C-C Multiple Bonds
JACS 2002, 124, 3824.
ACIE 2004, 43, 3303.
Science 1998, 281, 1646.
21
Iodobenzene-Catalyzed Oxidation Reaction
4: p-iodotoluene
JACS 2005, 127, 12244.
ACIE 2005, 44, 6193.
Synlett 2006, 798.
Org. Lett. 2005, 7, 2933.
Chem. Commun. 2006, 2483.
65% yield
25% ee
Synlett 2007, 538.
Chem. Commun. 2007, 1224.
22
This Work 1: Optimization of Condition
Directly related stoichiometric oxidation
using hypervalent iodine reagent
Assumption: Can PhI be oxidized in situ?
JACS 2007, 129, 2772.
possible mechanism for oxidative cleavage
Tableより、
・
=
=
・
・
・
添加剤等について
・
・
・
best
23
This Work 2: Substrate Scope of Oxidation
・
・
・
・
24
This Work 3: Proposed Catalytic Cycle
Proposed catalytic cycle
Kinetics to show the pre-equilibrium
Detection of intermediate by CSI-MS
special case of Michaelis-Menten
What can we do next?......
25
現代化学における情報戦③:参考文献デジタルライブラリ
参考文献を紙で整理するのはもう古い?
ReadCube
Evernote
Mendeley
Papers
新着論文チェックはRSSで!
26
化学ポータルサイトChem-Station紹介記事
http://www.chem-station.com/blog/2011/11/-readcube.html
http://www.chem-station.com/blog/2010/04/post-155.html
http://www.chem-station.com/blog/2009/03/-evernotepdf.html
EndNote
紙でプリントアウトする利点もまだまだある
・パソコンやタブレットが無くても読める
・一部切り抜いて実験ノートに貼り付け可能
・ペンで書き込みすることが可能
化学ポータルサイトChem-Station紹介記事
http://www.chem-station.com/yukitopics/topic_lifehack_1.htm
http://www.chem-station.com/blog/2009/11/rss.html
http://www.chem-station.com/blog/2009/01/-angewandte-chemierss.html
Chem-Stationより
「ものすごくかいつまんで言うなら、RSSとは「ニュースやブログなどの"最新見出しだけ"を記述したコード」のことです。
別の見方をすれば「更新状況に応じて最新の状態に保たれる、リアルタイム性のあるブックマーク」でもあります。」
RSSリーダーと呼ばれるソフトやウェブサイトを活用すると、自分が気になるブログやウェブサイトの更新状況がチェックできる
→ジャーナルの新着論文チェックに最適!いろいろなものが出回っているので「RSSリーダー」で検索すべし
他にも「有機化学美術館」など、普段からチェックすべきウェブサイトを
自分で見つけて化学を最大限楽しむべし!
Chem-Station代表
山口潤一郎 准教授
(名古屋大学伊丹研究室)
専門は新規合成反応開発を
基盤とした天然物合成など
最先端有機元素化学④:最新論文からのトピックス
27
Ona Illa, Muhammad Arshad, Abel Ros, Eoghan M. McGarrigle and Varinder K. Aggarwal
“Practical and Highly Selective Sulfur Ylide Mediated Asymmetric Epoxidations and Aziridinations
Using an Inexpensive, Readily Available Chiral Sulfide. Applications to the Synthesis of Quinine
and Quinidine”
タイトルとTOCグラフィックから読み取れること
J. Am. Chem. Soc. 2010, 132, 1828.
・
・
・
TOCから読み取れること
・
・
Heating one of the most abundant naturally occurring inorganic
chemicals (elemental sulfur) with one of the most readily available
homochiral molecules (limonene) gives a one-step synthesis of a chiral
sulfide which exhibits outstanding selectivities in sulfur ylide mediated
asymmetric epoxidations and aziridinations. In particular reactions of
benzyl and allylic sulfonium salts with both aromatic and aliphatic
aldehydes gave epoxides with perfect enantioselectivities and the
highest diastereoselectivities reported to date. In addition reactions with
imines gave aziridines again with the highest enantioselectivities and
diastereoselectivities reported to date. The reactions are scaleable, and
the sulfide can be reisolated in high yield. The epoxidation has been
used as the key step in a convergent and stereoselective synthesis of
each of the diastereoisomers of the cinchona alkaloids, quinine and
quinidine.
V. K. Aggarwal
University of Bristol
Limitation of Current Epoxidation By Sulfur Ylide
28
1,2-ジアリールエポキシドしか合成できない:
1,2-アリールアルキル体、α,β-不飽和体などは良い基質に
Org. Biomol. Chem. 2008, 6, 4502.
キラルなスルフィドの合成法が多段階に及ぶことが多い
JACS 1996, 118, 7004.
J. Org. Chem. 2005, 70, 4166.
Eur. J. Org. Chem. 2000, 1077.
Synlett 1999, 1328.
Tetrahedron Asymmetry 1991, 2, 367.
Chem. Commun. 2009, 5763.
Tetrahedron Lett. 2001, 42, 57.
J. Org. Chem. 2001, 66, 5620.
Tetrahedron Lett. 2002, 43, 5427.
Chem. Asian J. 2008, 3, 1657.
JACS 2003, 125, 10926.
Adv. Synth. Catal. 2008, 350, 2483.
29
This Work 1
キラルスルフィドのワンポット大量合成
Original report: JACS 1959, 81, 3430.
ベンジルスルホニウムイリドの反応
This Work 2
アリルスルホニウムイリドの反応
ベンジルスルホニウムイリドの反応によるアジリジン合成選択性の起源
30
This Work 3
合成戦略
→
Teoc:
Wikipediaにキニーネの全合成に関する面白い話が・・・
31
レポート課題について
s-またはp-ブロック元素の化合物に関する過去5年以内の論文を読み、
以下の点に関してA4用紙数枚程度にWORDファイルでまとめてPDFとし、
WORDおよびPDFの両方を8/15までに山下へemailで提出(学籍番号と名前を明記のこと)
[email protected]
(email提出後には一日以内に山下より返信します。無ければ届いていないので成績がつきません。)
各項目は後ろに行けば行くほど重要
・論文の背景においてどのような研究がなされてきたか?
要点を整理してまとめる。TOCの絵の貼り付け+論文内容の一言説明でもOK
・この論文において得られた結果は何か?
・この論文において何がこれまでの報告と違うのか?
・それはどのような工夫によって得られたものか?
・得られた結果を説明するための実験は他に考えられるか?
・自分ならこの論文に何を足してさらに次のアプローチを考えるか?
またそのアプローチに対して必要な他の事実を他の論文から探して
実現可能性に関して論ぜよ
ただし他の人と論文が重なってはいけない。
読むべき論文を決定した時点で山下へメールして重複の有無を確認すること。(学籍番号と名前を明記)
早く確認すればするほど論文を読む時間は増えるし、重複の可能性も少ない。
ラボの同級生・先輩・後輩・教員とのディスカッションはもちろんOKですが
最終的に自分の力で書ききることが最も自分の身になります。
成績評価は出欠代わりの小テストに加えて
レポート内容の論理性・妥当性を判定して絶対評価でつけます
(=全員Sも全員Dもありうる)
32