Stereo- And regio-selective synthesis of silicon-containing diborylalkenes: via platinum-catalyzed mono-lateral diboration of dialkynylsilanes

Article abstract of DOI:10.1039/d0cc00844c

A highly chemoselective platinum-catalyzed mono-lateral diboration of dialkynylsilanes for the construction of silicon-tethered alkynyl diborylalkenes is described, in which tris(4-methoxyphenyl)phosphine was found to be an effective ligand for the cis-addition of diboron agents to the silicon-tethered alkynes, and the chiral ligand (AFSi-Phos)-mediated diboration of dialkynylsilanes resulted in the desymmetric construction of silicon-stereogenic centers with promising enantioselectivity.

Full text of DOI:10.1039/d0cc00844c

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DOI: 10.1039/D0CC00844C
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Stereo- and Regio-Selective Synthesis of Silicon-Containing
Diborylalkenes via Platinum-Catalyzed Mono-Lateral Diboration
of Dialkynylsilanes
Received 00th January 20xx,
Accepted 00th January 20xx
Peng-Wei Long,a† Jia-Le Xie,a† Jing-Jing Yang,a Si-Qi Lu,a Zheng Xu,*a Fei Ye,a and Li-Wen Xu*ab
DOI: 10.1039/x0xx00000x
A
highly chemoselective platinum-catalyzed mono-lateral compounds and as highly versatile substrate sources for the
diboration of dialkynylsilanes for the construction of silicon- transformation of another alkynes to the construction of cyclic ring
tethered alkynyl diborylalkenes is described, in which the tris(4- structures.8,9 To the best of our knowledge, there are no reports
methoxyphenyl)phosphine was found to be an effective ligand for about mono-lateral diboration of dialkynlsilanes. Herein we
cis-addition of diboron agent to the silicon-tethered alkynes, and document a highly stereo- and chemoselective synthesis of silicon-
the chiral
ligand (AFSi-Phos) -mediated diboration of containing diborylalkenes via platinum-catalyzed mono-lateral
dialkynylsilanes resulted into desymmetric construction of silicon- diboration of dialkynlsilanes. The pronunced ligand effect and DFT
stereogenic center in promising enantioselectivity.
calculations suggest that diboration reactions initiated by oxidation
of the B-B bond to Pt and the rate-determining step is found to be
The organoboron compounds have been widely applied in phosphine dissocaitaion step.
organic and medicinal chemistry as building block1 due to their
versatile reactivity.2 Especially, the alkenylboron compounds are
a) Previous work:
Various
alkenylborons
compounds
R
R'
valuable synthon for varied natural product3 and electronic
M
R
R'
materials.4 In this context, the transition-metal-catalyzed boration
of alkynes is one of facile approaches to access alkenylboron
compounds, including diborylalkenes, that are essential elements in
functional materials and crucial intermediate for multisubstituted
alkenes, bioactive compounds, and π-conjugated materials.5 Over
the past years, transition-metal-catalyzed boration and diboration
reactions of alkynes have been extensively studied, in which the
borylation of internal and terminal alkynes with B2pin2 could be
achieved with defined regio- and stereochemistry (Figure 1a).6
Although catalytic diboration of alkynes with cis-selectivity is well
established, the discovery of a new catalyst can enhance the
synthetic efficiency of the boration and provide alternative
approach to the construction of structurally diverse organoboron
compounds. Based on our previous studies on silicon-mediated
organic synthesis (SiMOS),7 we are interested in the catalytic
synthesis of silicon-containing diborylalkenes and alkynes that have
potential capability of transformation into various organosilicon
cis-selectivity
Bpin
Bpin
M = Pt, Ir, Co, Cu, Pd, Au, Fe, et al.
b) This work:
Ar
Si
Ar
Pt/P-ligand
R
Mono-Lateral Borylation
cis-selectivity
Si
Bpin
R
Bpin
R
R
cis-product
The evaluation of P-ligands (>20) in this reaction
High yield
Broad substrate scope
Excellent stereo- & regioselectivity
OMe
P
3
P-Ligand
Figure 1 The synthesis of silicon-tethered alkynyl diborylalkenes through mono-lateral
diboration of dialkynylsilanes
We started our investigations with the reaction of di(hex-1-yn-1-
yl)(methyl)(phenyl)silane (1a) and B2pin2 (2a) with Pt(dba)3 as
catalyst. After screening of various phosphine ligands, the desired
mono-lateral diboration product 3a was accessed at 78% yield in
the presence of triphenylphosphine (Table 1, entry 9). And then the
best ligand was identified as tris(4-methoxyphenyl)phosphine,
which gave the desired cis-addition diborylalkene 3a in 83% yield
with >99:1 c.r. and 99:1 Z/E (Table 1, entry 14). Other phosphine
ligands, such as XantPhos, SPhos, DPEPhos, XPhos, JohnPhos and
phosphine ligands L1-L3 evaluated in this work, were found to be
no activities that totally suppress the reaction. Therefore, only the
triphenylphosphine and its derivatives that have a donor group at
a.Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of
Education, and Key Laboratory of Organosilicon Material Technology of Zhejiang
Province, Hangzhou Normal University, P. R. China
E-mail: zhengxu@hznu.edu.cn; liwenxu@hznu.edu.cn (XLW)
b.State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research
Institute and Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences,
P. R. China
† P.W. Long and J. L. Xie contributed equally to this work.
Electronic Supplementary Information (ESI) available: [details of any
supplementary information available should be included here]. See
DOI: 10.1039/x0xx00000x
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para-position of phenyl ring were suitable P-ligand in this In addition, running the reaction at 100 oC or 80VoieCw AlertdicletOonlainne
DOI: 10.1039/D0CC00844C
transformation (Table 1, entries 9 and 13-14). Notably, we did not increased yield with 90% or 95% respectively (Table 2, entries 13
determine formation of 4a that theoretically generated by double and 14).
diboration of 1a with 2 eq. of B2pin2, which revealed the good
Table 2 Optimization studies on the optimization of reaction parameters a
chemoselectivity of Pt/P(4-MeOPh)3 in this reaction. In addition, the
structure of 3a was determined by COSY and NOE spectra, which
signified the process of cis-addition across the reaction.
Table 1 Screen of ligands in the Pt-catalysed diboration of Si-linked bisalkyne 1aa
B2pin2 (1.2 eq)
n-Bu
Bpin
n-Bu
n-Bu
Bpin
Entry
Catalyst
Solvent
T
(oC)
50
50
50
50
50
50
50
50
50
50
60
80
100
80
Yield
(%)b
n.r
n.r
n.r
n.r
n.r
63
n.r
32
trace
n.r
73
91
Z/Ec
Pt(dba)3 (3 mol %)
Ligand (3 mol %)
Si
Si
Si
+
Bpin
Tol, 50 oC, 20 h
n-Bu
n-Bu
n-Bu
Bpin
3a
Bpin Bpin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
[Rh(COD)Cl]2
Pd2(dba)3
[Pd(η3-C3H5)Cl]2
[Ir(COD)Cl]2
[Ru(p-cymene)Cl]2
Pt(dba)3
Toluene
Toluene
Toluene
Toluene
Toluene
EA
-
-
-
-
1a
4a
Entry
ligand
3a/4ac
Yield (%)b
n.r.
n.r.
n.r.
n.r.
n.r.
n.r.
n.r.
n.r.
78
Z/E c
-
-
-
-
-
-
-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
XantPhos
RuPhos
t-Bu3P·HBF4
JohnPhos
XPhos
DPENPhos
Cy3P·HBF4
SPhos
-
-
-
-
-
-
-
-
-
99/1
-
99/1
-
Pt(dba)3
Pt(dba)3
Pt(dba)3
Pt(dba)3
Pt(dba)3
Pt(dba)3
Pt(dba)3
Pt(dba)3
DCM
THF
CH3CN
Hexane
Toluene
Toluene
Toluene
Toluene
-
99/1
98/2
97/3
99/1
-
PPh3
L1
L2
L3
>99:1
97/3
-
-
-
98/2
99/1
90
-
-
-
n.r.
n.r.
n.r.
72
95(88)d
a 1a (0.1 mmol), B2pin2 (0.12 mmol), catalyst and ligand (3 mol %) and solvent
(1 mL) at 50 oC for 20h. b Yields are determined by GC. c Determined by GC-MS
and confirmed by 1H-NMR. d Both the catalyst and ligand are 2 mol % in
solvent (0.5 mL), isolated yield is in parentheses.
P(p-toyl)3
P(4-MeOPh)3
>99:1
>99:1
83
a1a (0.1 mmol), B2pin2 (0.12 mmol), catalyst and ligand (3 mol %) and solvent (1
mL) at 50 oC for 20 h. b Yields are determined by GC. c The c.r. (3a/4a) and the
ratio of Z/E were determined by GC-MS and confirmed by 1H-NMR.
With the established optimal conditions in hand, we investigated
the substrates scope of mono-lateral diboration using a variety of
Si-linked bisalkynes 1a-1s bearing various substituted groups at the
aromatic ring or silicon center. As shown in Scheme 1, the
substrates 1a-1l that with varied substituents on the phenyl ring
reacted with B2pin2 efficiently to afford desired products in high
yields (76-90%) with >99:1 c.r. and high Z/E ratio (>99:1). When
electron-donating group (1c) on the para-position of phenyl rings
attached on silicon center, an improved yield was obtained (90%
yield for 3c). And the electron-withdrawing substituents would
slightly inhibit the reaction (76% yield for 3l). In fact, the variation
of alkyl substituents on phenyl group and alknyl group linked to the
silicon center did not play crucial role in this reaction. However,
when the introduction of phenylethyny and tert-butyl group at the
terminal alkyne and Si-center respectively, corresponding products
were obtained with decreased yields (43% yield for 3q and 55%
yield for 3r), which suggested the important role of steric repulsion
and electronic effect during the coordination of alkyne with Pt
catalyst for the formation of a -complex.
Based on our previous work on the enantioselective construction
of silicon-stereogenic organosilicon compounds,10 we envisaged
that chiral P-ligand can make a promising enantioselective induction
in the desymmetrization of Si-linked alkynes to give alkynyl Si-
stereogenic organoboron compounds. Then we screened various
chiral P-ligands under the optimized reaction conditions (Scheme 2
and see Table S5 and Table S6 in Supporting Information). It was
proved that the desymmetrization of prochiral Si-centered
PCy2
i-Pr
P(t-Bu)2
PCy2
Oi-Pr
i-Pr
O
PPh2
O
PPh2
i-PrO
PPh2
PPh2
DPEPhos
i-Pr
XantPhos
JohnPhos
RuPhos
XPhos
PCy2
OMe
PCy2
P
PPh2
PPh2
MeO
P
SPhos
L1
L2
L3
We next explored the catalytic activity of other transition-metal
complexes in the presence of tris(4-methoxyphenyl)phosphine.
Interestingly, the corresponding Pt(dba)3 complexes with P(4-
MeOPh)3 was the only effective catalyst for the highly
chemoselective mono-lateral diboration of Si-linked bisalkyne 1a,
and other metal complexes, e.g., [Rh(COD)Cl]2, Pd2(dba)3, [Pd(η3-
C3H5)Cl]2, [Ir(COD)Cl]2 and [Ru(p-cymene)Cl]2 were ineffective in this
reaction (Table 2, entries 1-5). These results suggested that the
oxidative addition of B-B bond to Pt is expected to be favored over
other metal catalysts. Based on these preliminary findings that the
Pt/P(4-MeOPh)3 was a suitable catalyst, the effect of solvents on
diboration revealed that toluene was superior to other solvents,
whereas other solvents involved polar and non-polar solvents
lowered yield or totally inhibited the reaction (Table 1, entries 6-11).
2 | J. Name., 2012, 00, 1-3
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dialkynlsilanes was not an easy task at present. After extensive
screening of chiral P-ligands, we found that only our Ar-NNPs11 and
its derivatives12 could be worked as an effective P-ligand to give
promising enantiomeric excess for the desired product Z-3a or E-3a’
(up to 73.5:26.5 er). And more importantly, the bulkyl and chiral P-
ligand could cause trans-addition of diboration to give unusal E-3a’
in moderate yield (Scheme 2). The DFT calculations for the Pt-
catalyzed diboration could provide useful information for the
unexpected diboration of Si-linked bisalkyne with E-selective
conversion.
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DOI: 10.1039/D0CC00844C
Scheme
2
Preliminary results for the enantioselective construction of silicon-
stereogenic center via desymmetric platinum-catalyzed mono-lateral diboration of
prochiral 1a with B2pin2.
Figure 2 Proposed catalytic cycle for Pt-catalyzed diboration of Si-linked bisalkynes.
TSCD-cis-s
-11.3
E(kcal/mol), B3LYP/6-31G(d,p)// LanL2DZ
Scheme 1 Substrates of scope. Reaction conditions: 1 (0.1 mmol), 2a (1.2 equiv),
Pt(dba)3 (2 mol %), P(4-MeOPh)3 (2 mol%), 20 h, 80 oC. Isolated yields were achieved
from flash column chromatograph.
TSCD-cis-r
-12.5
On the basis of the experimental results and DFT calculations (See
ESI, Figure S1-S5) 1-for the platinum-catalyzed diboration of
alkynes,6,13 we proposed a plausible catalytic cycle for the reaction
(Figure 2, path A is expected to be favored over path B). The adduct
C1 derived from the reaction of 2a and species O1 generated from
association of Pt(dba)3 with phosphine ligand was expected to react
with alkynyl moiety of 1a selectively, which led to intermediate D1
or E1 that possibly diverge into Z- or E-configuration intermediate
impacted by the bulkyl P-ligand. Finally, the reductive elimination of
intermediate F1 gave the desired product and Pt species O1. In this
regard, the mechanistic process gave important information that
the desymmetrization of prochiral dialkynylsilanes is not an easy
Cplx2-cis-s
-20.3
D-cis-r
-20.5
D-cis-s
-20.7
Cplx2-cis-r
-21.2
Figure 3 The energy profile [kcal/mol] for P-ligated Pt Catalyst [PtL1] of reaction. The
energy of A, B and P-ligated Pt complex [PtL1] is set to be relative zero reference (Also
see Figure S1-S5 and Table S9-S12 of Supporting information).
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
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J. Geier, A. I. MkhalidI, S. A. Westcott, T. B. Marder, Chem.
Rev. 2016, 116, 9091; (d) A. B. CuencaD, OR.I:S1h0.i1s0h3id9/oD,0HC.CI0to0,84E4. C
Fernández, Chem. Soc. Rev. 2017, 46, 415.
(a) A. B. Flynn, W. W. Ogilvie, Chem. Rev. 2007, 107, 4698; (b)
T. Hata, H. Kitagawa, H. Masai, T. Kurahashi, M. Shimizu, T.
Hiyama, Angew. Chem. Int. Ed. 2001, 40, 790; (c) X. Guo, A.K.
task because the energy profile for the formation of (S)-isomer and
(R)-isomer is very close (see Figure 3, 9.0 kcal/mol versus 8.7
kcal/mol). In addition, the steric repulsion of chiral phosphine ligand
L6 plays an essential role. The trans-adducts 3a’ shown in Scheme 2
could be produced through isomerization of 2-vinyl Pt-complex (E1
or E2) due to the less sterically hindrance between the Bpin-Pt-L6
and the other Bpin moiety in comparison to that of cis-addition
process The steric effect was also supported by the experiment
results that phosphine ligands (L3, L5 and L6) bearing a bulky group
produced E-isomer with high E/Z ratio (up to 44/56) that has never
been reported in previous literatures.6
View Article Online
5
6
Nelson, C. Slebodnick, W.L. Santos, ACS Catal. 2015,
(d) J. Bꢀhnke, H. Braunschweig, A. Deißenberger, T.
5, 2172;
Dellermann, R. D. Dewhurst, J.O.C. Jimꢁnez-Halla, S. Kachel,
H. Kelch, D. Prieschl, Chem. Commun. 2017, 53, 12132.
For platinum catalysis, see: (a) T. Ishiyama, N. Matsuda, N.
Miyaura, A. Suzuki, J. Am. Chem. Soc. 1993, 115, 11018; (b) T.
Ishiyama, N. Matsuda, M. Murata, F. Ozawa, A. Suzuki, N.
Miyaura, Organometallics 1996, 15, 713; (c) G. Lesley , P.
In summary, we have developed a novel platinum-catalyzed
mono-lateral diboration of prochiral Si-linked dialkynylsilanes with
B2pin2. It was found that the employment of a monophosphine
ligand P(4-MeOPh)3 led to facile synthesis of a series of silicon-
containing diborylalkenes in high yields with good stereo- and
Nguyen, N. J. Taylor, T. B. Marder, Organometallics 1996, 15
5137; (d) R. L. Thomas, F. E. S. Souza, T. B. Marder, J. Chem.
,
Soc., Dalton Trans. 2001, 1650; (e) H. Prokopcova, J. Ramirez,
E. Fernandez, O. C. Kappe, Tetrahedron Lett. 2008, 49, 4831;
(f) N. Iwadate, M. Suginome, J. Am. Chem. Soc. 2010, 132
,
2548; (g) J. Jiao, K. Hyodo, H. Hu, K. Nakajima, Y. Nishihara, J.
Org. Chem., 2014, 79, 285; (h) H. Yoshida, K. Okada, S.
regioselectivities.
Preliminary
studies
suggested
that
enantioselective construction of silicon-stereogenic Si-linked
diborylalkenes via this platinum-catalyzed mono-lateral diboration
of prochiral dialkynylsilanes is a challenging task, in which our new
AFSi-Phos gave the best enantioselectivity. Further work on the
exploration of conceptually new ligand for the enantioselective
diboration of alkynes is currently in progress.
Kawashima, K. Tanino, J. Ohshita, Chem. Commun., 2010, 46
,
1763. For cobalt catalysts, see: (i) J. Christopher, R. Adams, Z.
Lin, B. Marder, C. Nicholas, A. G. Orpena, Dalton Trans. 2006,
1370. For copper catalysts, see: (j) V. Lillo, M. R. Fructos, J.
Ramírez, A. A. C. Braga, F. Maseras, M. M. Díaz-Requejo, P.
Fernández, Chem. Eur. J. 2007, 13, 2614; (k) H. Yoshida, S.
Kawashima, Y. Takemoto, K. Okada, J. OhShita, K. Takaki,
Angew. Chem. Int. Ed. 2012, 51, 235. For gold catalysts, see:
(l) Q. Chen, J. Zhao, Y. Ishikawa, N. Asao, Y. Yamamoto, T-N.
Jin, Org. Lett., 2013, 15, 5767. For iron catalysts, see: (m) N.
Nakagawa, T. Hatakeyama, N. Nakamura, Chem. Eur. J. 2015,
21, 4257. For palladium catalysts, see: (n) B. Melvyn H. Vitor,
A.C. Braga, J. Spencer, O. Navarro, Catal. Sci. Technol., 2016,
We are grateful to the NSFC of China (No. 21773051, 21703051,
21801056, and 21901056), and Zhejiang Provincial Natural Science
Foundation of China (LZ18B020001, LQ 19B040001, and
LY18B020013). This work is also supported partially by Hangzhou
Science and Technology Bureau of China (20170533B08 and
20180432B05).
6
, 7461; (o) Z. Yang, T. Cao, Y. Han, W. Zhang, T. Zhu, S-M.
Ma, Chin. J. Chem. 2017, 35, 1251. For iridium catalysts, see:
(p) C. I. Lee, W-C. Shi, J. Zhou, J. H. Reibenspies, O.V. Ozerov,
Angew. Chem. Int. Ed. 2015, 54, 14003; (q) N. Iwadate, M.
Suginome, J. Am. Chem. Soc. 2010, 132, 2548. For metal-free
protocols, see: (r) H. Schlesinger, T. Parsons, J. Kerrigan, G.
Urry, J. Am. Chem. Soc. 1954, 76, 5299; (s) M. Zeldin, A. R.
Gatti, T. Watrik, J. Am. Chem. Soc. 1967, 89, 4217; (t) R. W.
Rudolph, J. Am. Chem. Soc. 1967, 89, 4216; (u) S. Peng, G.X.
Liu, Z. Huang, Org. Lett. 2018, 20, 7363; (v). Z. Kuang, G-L.
Gao, Q-L. Song, Sci. China. Chem. 2019, 62, 62.
Conflicts of interest
There are no conflicts to declare.
Notes and references
1
(a) S. Jin, Y. Cheng, S. Reid, M. Li, B. Wang, Med. Res. Rev.
2010, 30, 171; (b) D. Luvino, D. Gasparutto, S. Reynaud, M.
Smietana, J. J. Vasseur, Tetrahedron Lett. 2008, 49, 6075; (c)
D. Luvino, M. Smietana, J. J. Vasseur, Tetrahedron Lett. 2006,
47, 9253; (d) S. D. Bull, M. G. Davidson, J. M. H. van den Elsen,
J. S. Fossey, A. T. A. Jenkins, Y.-B. Jiang, Y. Kubo, F. Marken, K.
Sakurai, J. Zhao, T. D. James, Acc. Chem. Res. 2013, 46, 312;
(e) N. Christinat, R. Scopelliti, K. Severin, Angew. Chem. Int.
Ed. 2008, 47, 1848; (f) A. L. Korich, P. M. Iovine, Dalton Trans.
2010, 39, 1423; (g) M. Scholz, E. Hey-Hawkins, Chem. Rev.
2011, 111, 7035; (h) A. R. Martin, J. J. Vasseur, M. Smietana,
Chem. Soc. Rev. 2013, 42, 5684.
(a) N. Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457; (b) A.
Suzuki, J. Organomet. Chem. 1999, 576, 147; (c) C. M.
Crudden, B. W. Glasspoole, C. J. Lata, Chem. Commun. 2009,
6704; (d) I. Georgiou, G. Ilyashenko, A. Whiting, Acc. Chem.
Res. 2009, 42, 756; (e) A. J. J. Lennox, G. C. Lloyd-Jones,
Chem. Soc. Rev. 2014, 43, 412.
7
8
9
L. Li, Y. L. Wei, L. W. Xu, Synlett, 2020, 31, 21–34, and
references cited therein.
T. Ohmura, Y. Morimasa, M. Suginome, Chem. Lett. 2017, 46
1793.
,
(a) K. Gilmore, I. V. Alabugin, Chem. Rev., 2011, 111, 6513. (b)
J. Xu, A. studer, Chem. Soc. Rev., 2017, 46, 4329.
10 (a) X. Lu, L. Li, W. Yang, K. Jiang, K.-F. Yang, Z.-J. Zheng, L.-W.
Xu, Eur. J. Org. Chem. 2013, 5814; (b) L. Chen, J.-B. Huang, Z.
Xu, Z.-J. Zheng, K.-F. Yang, Y.-M. Cui, J. Cao, L.-W. Xu, RSC
Adv., 2016, 6, 67113; (c) P.-W. Long, X.-F. Bai, F. Ye, L. Li, Z.
Xu, K.-F.Yang, Y.-M. Cui, Z.-J. Zheng, L.-W. Xu, Adv. Synth.
Catal. 2018, 360, 2825; (d) Y. Lin, W.-Y. Ma, Z. Xu, Z.-J. Zheng,
J. Cao, K.-F. Yang, Y.-M. Cui, L.-W. Xu, Chem. Asian J. 2019, 14
2082.
2
,
11 L-S. Zheng, L. Li, K-F. Yang, Z-J. Zheng, X-Q. Xiao, L-W. Xu,
Tetrahedron. 2013, 69, 8777.
12 The experimental procedure of new P-ligand L6 (simplified as
AFSi-Phos) was provided in the Supporting Information. The
importance of silicon-based bulky group has been revealed
in our previous work: F.-N. Sun, W.-C. Yang, X.-B. Chen, Y.-L.
Sun, J. Cao, Z. Xu, L.-W. Xu, Chem. Sci., 2019, 10, 7579.
13 Q. Cui, D. G. Musaev, K. Morokuma, Organometallics 1997,
16, 1355.
3
4
(a) K. Roupe, C. Remsberg, J. Yanez, N. Davies, Curr. Clin.
Pharm. 2006, 1, 81; (b) C. H. Cottart, V. Nivet-Antoine, J. L.
Beaudeux, Mol. Nutr. Food. Res. 2014, 58, 7; (c) L. Xu, S.
Zhang, P. Li, Chem. Soc. Rev. 2015, 44, 8848.
(a) H. Meier, Angew. Chem. Int. Ed. 1992, 31, 1399; (b) S. C.
Lo, P. L. Burn, Chem. Rev. 2007, 107, 1097; (c) E. C. Neeve, S.
4 | J. Name., 2012, 00, 1-3
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