Reactions of a ditriptycyl-substituted selenoseleninate and related compounds with a platinum(0) complex: Formation of selenaplatinacycle and hydrido selenolato platinum(II) complexes

Article abstract of DOI:10.1002/anie.200705336

(Figure Presented) A selenaplatinacycle (see structure 1; red P, blue Pt, greenSe) is formed by the reactions of TripSe(O)SeTrip (Trip = 9-triptycyl) and TripSeOH with [Pt(PPh₃)₂-(η²-C ₂H₄)] by intram

Full text of DOI:10.1002/anie.200705336

Angewandte
Chemie
DOI: 10.1002/anie.200705336
Selenium Metallacycles
Reactions of a Ditriptycyl-Substituted Selenoseleninate and Related
Compounds with a Platinum(0) Complex: Formation of
Selenaplatinacycle and Hydrido Selenolato Platinum(II) Complexes**
Akihiko Ishii,* Norio Nakata, Rei Uchiumi, and Keiko Murakami
Dedicated to Professor Renji Okazaki on the occasion of his 70th birthday
we report the reactions of 1 and its related compounds with a
Oxidative additions of cyclic and acyclic disulfides and their
oxides to platinum(0) complexes are a topic of recent
research.[1–3] However,analogous reactions of selenium com-
pounds are limited to diselenides.[3,4] For example,in the
diselenation of terminal acetylenes with diselenides in the
presence of palladium(0) and platinum(0) complexes,[5,6]
diselenolato complexes have been proposed as the inter-
mediates. As far as we know,there are no reports on
analogous reactions for oxides of diselenides such as seleno-
seleninates (RSe(O)SeR),a major reason for which must be
that only few isolable selenoseleninates are known.[7,8] It is
important to investigate their reactivity toward low-valent
transition-metal complexes and the nature of the resulting
selenium metal complexes in relation to the corresponding
chemistry of sulfur.
platinum(0) complex. We unexpectedly observed the forma-
tion of a five-membered selenaplatinacycle by intramolecular
[9]
À
C H activation. The chemistry of chalcogenametallacycles
is also interesting in relation to the mechanistic study of
homogeneous hydrodesulfurization of crude oil distillates.
The formation of thiaplatinacycles 5[10] and selenametalla-
cycles 6[11] by insertion of low-valent transition metals into C
À
Previously we reported the preparation of selenoseleni-
nate 1 by dehydration of selenenic acid 2 or oxidation of
diselenide 3 (Scheme 1).[7] Selenoseleninates 1 and 4 are the
only such species isolable under ambient conditions. Herein
À
S and C Se bonds of the thiophene and selenophene
derivatives,respectively,has been revealed.
We first examined the reaction of selenoseleninate 1 with
[Pt(PPh3)2(h2-C2H4)] (7) in the expectation of obtaining the
corresponding selenenato selenolato platinum(II) complex
[Pt(SeTrip){Se(O)Trip}(PPh3)2]. However,when
1 was
treated with 1.1 molar equivalents of 7 in toluene at room
temperature,we obtained an unexpected compound ( 8,0.72
molar equiv) together with diselenide 3 (0.30 molar equiv,
30%) [Eq. (1)]. In the 31P NMR spectrum of the compound,
Scheme 1. Formation of selenoseleninates from selenenic acids and
diselenides.
[*] Prof. Dr. A. Ishii, Dr. N. Nakata, R. Uchiumi, K. Murakami
Department of Chemistry
Graduate School of Science and Engineering, Saitama University
255 Shimo-okubo, Sakura-ku, Saitama 338-8570 (Japan)
Fax: (+81)48-858-3700
E-mail: ishiiaki@chem.saitama-u.ac.jp
Homepage: http://www.chem.saitama-u.ac.jp/ishii-lab/index.files/
slide0001.htm
two doublets with accompanying satellite signals from the
2
195Pt isotope are observed at d = 22.7 (d, J(P,P) = 20.4 Hz,
1J(Pt,P) = 1833 Hz) and 25.3 ppm (d, 2J(P,P) = 20.4 Hz, 1J-
1
(Pt,P) = 3276 Hz). In the H NMR spectrum,a characteristic
[**] This work was supported by a Grant-in-Aid for Science Research on
Priority Areas (No. 19027014, Synergy of Elements) from Ministry of
Education, Culture, Sports, Science and Technology (Japan).
signal appears at d = 5.81–5.88 ppm (m,1H). The structure
was finally shown by X-ray crystallography to be selenapla-
tinacycle 8 (Figure 1). The signal in the 31P NMR spectrum at
d = 25.3 ppm with 1J(Pt,P) = 3276 Hz was assigned to the
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the triphenylphosphane ligands,which hinder the combina-
tion of 9 and TripSeOÀ and permit reaction of the metal
À
center in 9 with the C H bond of the 9-triptycyl group.
Incidentally,diselenide 3 would be formed by deoxygenation
of 1 with triphenylphosphane liberated under the reaction
conditions. In a separate experiment,the deoxygenation of 1
with triphenylphosphane took place readily to give diselenide
3 and triphenylphosphane oxide quantitatively.
If the reaction mechanism in Scheme 2 is operative,
selenenic acid 2,which is stable in solution at room temper-
ature,[7] should be formed. However,we did not obtain 2,
suggesting that 2 also reacts with 7 to give selenaplatinacycle
8. This consideration was confirmed by the reaction of 2 with
7 to give 8 in 94% yield [Eq. (2)]. This reaction would
Figure 1. ORTEP drawing of 8. Thermal ellipsoids are set at 30%
probability. Hydrogen atoms and the solvent molecule were omitted
for clarity. Selected bond lengths [Š] and angles [8]: Pt1–C3 2.099(4),
Pt1–P2 2.2975(10), Pt1–P1 2.3318(10), Pt1–Se1 2.4097(4); C3-Pt1-P2
92.78(11), P2-Pt1-P1 95.70(4), C3-Pt1-Se1 85.65(10), P1-Pt1-Se1
85.86(3), C3-Pt1-P1 171.36(10), P2-Pt1-Se1 178.44(3).
proceed in a manner similar to that in Scheme 2,except that
H2O would be formed in this case. Thus two mole 8 should be
formed from one mole 1,and the yield of 8 in Equation (1) is
36%.
We occasionally observed two intermediates for 8 in the
31P NMR spectra of reaction mixtures of 1 and 7 and of 2 and
7. Though we have not yet succeeded in isolating these
intermediates,we tentatively assigned them as cis and trans
hydroxo complexes 10a and 10b on the basis of the substrates
P atom trans to the Se atom. The 1J(Pt,P) value is comparable
to those of reported (selenolato)PtII complexes.[3,4] The
1J(Pt,P) value (1833 Hz) of the other doublet (assigned to
the P atom trans to the C atom) is very similar to those of
thiaplatinacycles 5a (1777 Hz), 5c (1691 Hz),and
5e
(1645 Hz).[10e]
À
À
In 8,the Pt1 P1 bond (2.3318(10) Š) trans to the Pt1 C3
À
bond is longer than the Pt1 P2 bond (2.2975(10) Š) trans to
À
the Pt1 Se1 bond. This observation,as well as the smaller
1J(Pt,P) value of P1 than of P2, indicates that the trans
influence of the aromatic C atom is larger than that of the
Se atom. The Pt atom maintains the planarity of tetracoordi-
nated PtII atoms; the sum of the four angles around the
Pt atom is 359.998. The P2-Pt1-P1 angle widens to 95.70(4)8.
A plausible formation mechanism for selenaplatinacycle 8
is depicted in Scheme 2. The attack of Pt(PPh3)2 at the
divalent selenium atom in selenoseleninate 1 takes place first
to give a cationic intermediate 9 and TripSeOÀ. An intra-
molecular substitution reaction of 9 leads to the selenaplati-
nacycle 8,where TripSeO À acts as a base to abstract a proton
from 9 to form selenenic acid 2. The lack of formation of the
presumed selenenato selenolato platinum(II) complex is
probably due to the bulkiness of the 9-triptycyl group and
employed and the comparison of the 1J(Pt,P) values with
those of reported hydroxo PtII complexes.[12] In the 31P NMR
spectrum, 10a exhibited two doublets with accompanying
satellite signals from the 195Pt isotope at d = 16.9 (d, 2J(P,P) =
19.5 Hz, 1J(Pt,P) = 3249 Hz) and 19.7 ppm (d, 2J(P,P) =
19.5 Hz, 1J(Pt,P) = 3017 Hz),and 10b showed a singlet at
d = 8.6 ppm (1J(Pt,P) = 3755 Hz). These intermediates were
transformed into 8 quantitatively in solution at room temper-
ature within several hours.
The above two reactions are summarized as follows:
TripSe-LG reacts with Pt0 complex 7,giving rise to selena-
platinacycle 8,in which LG is the leaving group in the initial
nucleophilic attack of 7 and the resulting LGÀ behaves as a
base in the subsequent cyclometalation. To investigate the
generality of this reaction,we next examined the reaction of
diselenide 3 with 7. The reaction of 3 with an equimolar
amount of 7 was performed at room temperature,and we
obtained 8 (42%),hydrido selenolato platinum(II) complex
12 (30%),and selenol 11 (9.7%); diselenide 3 (51%) was also
recovered [Eq. (3)]. Conversion yields of 8, 12,and 11 were
85%,61%,and 20%,respectively.
Thus,the reaction of diselenide 3 with 7 produced
selenaplatinacycle 8 and selenol 11 as expected,and,inter-
Scheme 2. Aplausible mechanism for the reaction of selenoseleninate
1 with [Pt(PPh3)2(h2-C2H4)] (7) to give selenaplatinacycle 8.
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estingly,the selenol 11 reacted with 7 to give the hydrido PtII
complex 12. When a sufficient amount (two molar equiv-
distorted. While the P1-Pt1-Se1 bond angle (91.10(3) Š) is
near 908,the P1-Pt1-P2 bond angle widens to 100.87(4) 8; this
value is larger by about 58 than the corresponding angle in
selenaplatinacycle
8 (95.70(4)8). In hydroselenation of
alkynes employing selenols in the presence of Pt0 cata-
lysts,[13,14] hydrido selenolato platinum(II) complexes were
proposed as key intermediates.[13a] Ananikov et al. succeeded
1
in the observation of trans-[Pt(H)(SePh)(PPh3)2] by H and
31P NMR spectroscopy. The configuration of the two phos-
phane ligands in 12 is cis,in contrast to trans-[Pt(H)(SePh)-
1
(PPh3)2] of Ananikov et al. In the H NMR spectrum of 12,
the proton bound to the Pt atom resonates at d = À6.10 ppm
2
alents) of 7 was employed, 8 and 12 were obtained in 80% and
with J(P,H) couplings of 16 and 184 Hz and with satellite
88% yields,respectively,together with a small amount of
3
signals from the 195Pt isotope separated by 1523 Hz. In
contrast,no 2J(P,H) coupling was observed for trans-[Pt-
(PPh3)2(PhSe)(H)] (1H NMR: d = À8.77 ppm, J(Pt,H) =
999.8 Hz, J(Se,H) = 44.1 Hz). Interestingly,treatment of 12
with HBF4 provided selenaplatinacycle 8 in 60% yield
(Scheme 3). Elimination of a hydride (HÀ) from 12 under
strongly acidic conditions would generate the cationic inter-
mediate 9,which then proceeds to form 8,thus supporting the
mechanism in Scheme 2.
(7%). This result is in marked contrast to the previously
reported reactions of other diselenides (RSeSeR) with
smaller R groups to give the corresponding (diselenolato)PtII
complexes.[3,4]
Hydrido selenolato platinum(II) complex 12 was obtained
in pure form by the reaction of selenol 11 with 7 (Scheme 3).
Complex 12 is stable under ambient conditions,and the
In conclusion,we found that the reactions of selenosele-
ninate 1,selenenic acid 2,and diselenide 3,which have a 9-
triptycyl group,with [Pt(PPh 3)2(h2-C2H4)] 7 gave selenaplati-
À
nacycle 8 by intramolecular C H bond activation. We also
succeeded for the first time in the full characterization of a
hydrido selenolato platinum(II) complex (12). These results
will give a new insight into the reaction of selenium
compounds with low-valent transition-metal complexes. In
the formation of 8,bulkiness of the substituents both on the
selenium atom in 1 and on the platinum atoms in 7 play an
important role. The generality of this reaction is under
investigation,focusing both on the substituents of the organic
selenium compounds and on the phosphane ligands and
metals of low-valent transition metal-complexes.
Scheme 3. The reaction of selenol 11 with 7 giving the hydrido
selenolate platinum(II) complex 12 and the reaction of 12 with HBF4
to give selenaplatinacycle 8.
structure was confirmed unambiguously by X-ray crystallo-
graphic analysis (Figure 2). The sum of the four angles around
the Pt atom is 365.48,and the planarity of the Pt atom is
Experimental Section
Reaction of 1 with 7: A solution of 7 (58.3 mg,0.0780 mmol) in
toluene (5 mL) was added dropwise at room temperature to a
solution of 1 (47.9 mg,0.0704 mmol) in toluene (5 mL) under argon.
The mixture was stirred for 1 h at room temperature and then the
solvent was removed in vacuo. The mixture was subjected to column
chromatography (silica gel). Di-9-triptycyldiselenide (3,14.0 mg,
0.021 mmol,30%) was first eluted with hexane/dichloromethane
(1:1),and then the column was eluted with dichloromethane to give
selenaplatinacycle
8
(53.4 mg,0.0508 mmol,36%).
8: colorless
crystals,m.p. 286–288 8C (decomp). 1H NMR (400 MHz,CDCl
258C,TMS): d = 5.22 (s,1H),5.81–5.88 (m,1H),6.65–6.71 (m,2H),
,
3
6.90–6.98 (m,10H),7.13 (pseudo t, J = 6.9 Hz,3H),7.21 (dt, J = 7.7,
1.9 Hz,6H),7.25–7.36 (m,11H),7.62–7.68 (m,6H),7.98 ppm
(pseudo d, J = 7.6 Hz,2H). Elemental analysis calcd (%) for
C57H44Cl2P2PtSe (C56H42P2PtSe·CH2Cl2): C 60.27,H 3.86; found:
Figure 2. ORTEP drawing of cis-[Pt(H)(SeTrip)(PPh3)2] 12. Thermal
ellipsoids are set at 30% probability. Hydrogen atoms except H1 and
the solvent molecules were omitted for clarity. Selected bond lengths
[Š] and angles [8]: Pt1–P2 2.2474(12), Pt1–P1 2.3295(12), Pt1–Se1
2.4272(5), Pt1–H1 1.69(5); P2-Pt1-P1 100.87(4), P1-Pt1-Se1 91.10(3),
P2-Pt1-H1 85.65(10), Se1-Pt1-H1 87.8(16), P2-Pt1-Se1 166.89(3), P1-
Pt1-H1 178.9(16).
C 60.74,H 3.90.
Crystallographic
data:
C
63H50P2PtSe
(C56H42P2PtSe·C7H8), Ms = 1143.02,colorless prism,0.25 ” 0.25 ”
0.20 mm3,monoclinic,space group
P21/c, a = 13.9733(8), b =
16.8802(10), c = 20.5325(13) Š, b = 91.374(2)8, V= 4841.7(5) Š3,
1calcd = 1.568 gcmÀ3, Z = 4, m(MoKa) = 3.758 cmÀ1. Intensity data of
9503 unique reflections were collected in the range of À16 ꢀ h ꢀ 17,
À20 ꢀ k ꢀ 20, À16 ꢀ l ꢀ 25 at 183 K. R1 = 0.0346 (I ꢁ 2sI,7858 reflec-
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Communications
tions), wR2 = 0.0846 (all data),GOF = 1.025,688 parameters,max/
[5] H. Kuniyasu,A. Ogawa,S.-I. Miyazaki,I. Ryu,N. Kambe,N.
Sonoda, J. Am. Chem. Soc. 1991, 113,9796 – 9803.
[6] V. P. Ananikov,I. P. Beletskaya,G. G. Aleksandrov,I. L. Ere-
menko, Organometallics 2003, 22,1414 – 1421.
À3
min residual electron density = 1.474/À0.594 eŠ
.
12: colorless crystals,m.p. 158–160 8C (decomp),recrystallized
1
2
from a toluene/hexane solution. H NMR: d = À6.10 (dd, J(P,H) =
184,16 Hz, 1J(H,Pt) = 1523 Hz),5.29 (s,1H),6.88–7.01 (m,12H),
7.12–7.32 (m,21H),7.58–7.63 (m,6H),8.38 ppm (br s,3H);
31P NMR: d = 21.3 (d, 2J(P,P) = 14.0 Hz, 1J(Pt,P) = 3281 Hz),
30.9 ppm (d, 2J(P,P) = 14 Hz, 1J(Pt,P) = 2028 Hz); IR (KBr): n˜ =
[7] A. Ishii,S. Matsubayashi,T. Takahashi,J. Nakayama,
Chem. 1999, 64,1084 – 1085.
J. Org.
[8] a) H. J. Reich,C. A. Hoeger,W. W. Willis,Jr., J. Am. Chem. Soc.
1982, 104,2936 – 2937; b) H. J. Reich,C. A. Hoeger,W. W.
Willis,Jr., Tetrahedron 1985, 41,4771 – 4779.
2093 cmÀ1 (Pt H). Elemental analysis calcd (%) for C56H44P2PtSe:
À
À
C 63.88,H 4.21; found: C 63.33,H 4.13. Crystallographic data:
[9] a) “Activation and Functionalization of C H bonds”: A. S.
C63H50P2PtSe (C56H42P2PtSe·1.5C7H8), Ms = 1190.62,colorless prism,
Goldman,K. I. Goldberg, ACS Symp. Ser. 2004, 885,1 – 43;
b) S. M. Hubig,S. V. Lindeman,J. K. Kochi, Coord. Chem. Rev.
2000, 200–202,831 – 873; c) G. W. Parshall, Acc. Chem. Res.
1975, 8,113 – 117; d) G. W. Parshall, Acc. Chem. Res. 1970, 3,
0.25 ” 0.25 ” 0.20 mm3,triclinic,space group P1. a = 12.4546(6), b =
¯
14.5548(7), c = 16.8369(8) Š, a = 93.8360(10), b = 102.4290(10), g =
115.0090(10)8, V= 2657.8(2) Š3, 1calcd = 1.488 gcmÀ3
,
Z = 2, m-
(MoKa) = 3.426 cmÀ1. Intensity data of 9880 unique reflections were
collected in the range of À15 ꢀ h ꢀ 14, À17 ꢀ k ꢀ 14, À20 ꢀ l ꢀ 20 at
123 K. R1 = 0.0360 (I ꢁ 2sI,8664 reflections), wR2 = 0.0840 (all data),
139 – 144; e) M. Albrecht,A. L. Spek,G. van Koten,
J. Am.
Chem. Soc. 2001, 123,7233 – 7246; f) H. A. Zhong,J. A.
Labinger,J. E. Bercaw, J. Am. Chem. Soc. 2002, 124,1378 –
1399; g) L. Johansson,M. Tilset,J. A. Labinger,J. E. Bercaw, J.
Am. Chem. Soc. 2000, 122,10846 – 10855; h) C. N. Iverson,R. J.
Lachicotte,C. Müller,W. D. Jones, Organometallics 2002, 21,
5320 – 5333; i) M. D. K. Boele,G. P. F. van Strijdonck,A. H. M.
de Vries,P. C. J. Kamer,J. G. de Vries,W. N. M. van Leeuwen, J.
Am. Chem. Soc. 2002, 124,1586 – 1587; j) D. L. Davies,S. M. A.
Donald,S. A. Macgregor, J. Am. Chem. Soc. 2005, 127,13754 –
13755; k) R. A. Periana,X. Y. Liu,G. Bhalla, Chem. Commun.
2002,3000 – 3001.
GOF = 1.009,647 parameters,max/min residual electron density
=
À3
1.566/À0.566 eŠ
.
CCDC-666761 (8) and CCDC-666762 (12) contain the supple-
mentary crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
Received: November 21,2007
Published online: February 27,2008
[10] a) J. J. Garcia,P. M. Maitlis, J. Am. Chem. Soc. 1993, 115,12200 –
12201; b) D. A. Vicic,W. D. Jones, Organometallics 1998, 17,
3411 – 3413; c) C. A. Dullaghan,X. Zhang,D. L. Greene,G. B.
Carpenter,D. A. Sweigart,C. Camiletti,E. Rajaseelan, Organo-
metallics 1998, 17,3316 – 3322; d) H. Li,G. B. Carpenter,D. A.
Sweigart, Organometallics 2000, 19,1823 – 1825; e) G. Picazo,A.
ArØvalo,S. Bern›s,J. J. García, Organometallics 2003, 22,4734 –
4738.
[11] a) A. J. Arce,A. J. Deeming,Y. De Sanctis,R. Machado,J.
Manzur,C. Rivas, J. Chem. Soc. Chem. Commun. 1990,1568 –
1569; b) A. J. Arce,R. Machado,C. Rivas,Y. De Sanctis,A. J.
Deeming, J. Organomet. Chem. 1991, 419,63 – 75; c) M.-G. Choi,
R. J. Angelici, J. Am. Chem. Soc. 1991, 113,5651 – 5657; d) C. J.
White,R. J. Angelici, Organometallics 1995, 14,332 – 340;
À
Keywords: C H activation · cyclometalation · hydride ligands ·
platinum · selenium
.
[1] a) W. Weigand,S. Bräutigam,G. Mloston, Coord. Chem. Rev.
2003, 245,167 – 175; b) W. Weigand,G. Bosl,C. Robl,W.
Amrein, Chem. Ber. 1992, 125,1047 – 1051; c) W. Weigand,R.
Wünsch, Chem. Ber. 1996, 129,1409 – 1419; d) W. Weigand,R.
Wünsch,K. Polborn,G. Mloston, Z. Anorg. Allg. Chem. 2001,
627,1518 – 1522; e) W. Weigand,R. Wünsch,C. Robl,G.
Mloston,H. Nöth,M. Schmidt,
Z. Naturforsch. B 2000, 55,
453 – 458; f) R. Wünsch,W. Weigand,G. Nuspl, J. Prakt. Chem.
1999, 341,768 – 772; g) W. Weigand,R. Wünsch,K. Polborn,
Inorg. Chim. Acta 1998, 273,106 – 110.
e) D. A. Vicic,A. W. Myers,W. D. Jones,
Organometallics
1997, 16,2751 – 2753; f) D. S. Choi,I. S. Lee,S. U. Son,Y. K.
Chung, Organometallics 2001, 20,3617 – 3620; g) K. Yu,H. Li,
E. J. Watson,K. L. Virkaitis,G. B. Carpenter,D. A. Sweigart,
Organometallics 2001, 20,3550 – 3559.
[2] a) A. Ishii,M. Saito,M. Murata,J. Nakayama, Eur. J. Org. Chem.
2002,979 – 982; b) A. Ishii,T. Kawai,M. Noji,J. Nakayama,
Tetrahedron Lett. 2005, 61,6693 – 6699; c) A. Ishii,M. Murata,
H. Oshida,K. Matsumoto,J. Nakayama, Eur. J. Inorg. Chem.
2003,3716 – 3721; d) A. Ishii,S. Kashiura,Y. Hayashi,W.
Weigand, Chem. Eur. J. 2007, 13,4326 – 4333; e) A. Ishii,M.
Ohishi,N. Nakata, Eur. J. Inorg. Chem. 2007,5199 – 5206.
[3] a) S. M. Aucott,H. L. Milton,S. D. Robertson,A. M. Z. Slawin,
G. D. Walker,J. D. Woollins, Chem. Eur. J. 2004, 10,1666 – 1676;
b) S. M. Aucott,P. Kilian,S. D. Robertson,A. M. Z. Slawin,J. D.
Woollins, Chem. Eur. J. 2006, 12,895 – 902.
[12] a) C. Scriban,D. S. Glueck,J. A. Golen,A. L. Rheingold,
Organometallics 2007, 26,1788 – 1800; b) B. F. Straub,F.
Rominger,P. Hofmann, Inorg. Chem. Commun. 2000, 3,214 –
217.
[13] a) V. P. Ananikov,D. A. Malyshev,I. P. Beletskaya,G. G.
Aleksandrov,I. L. Eremenko, J. Organomet. Chem. 2003, 679,
162 – 172; b) V. P. Ananikov,N. V. Orlov,I. P. Beletskaya,
Organometallics 2007, 26,740 – 750.
[4] R. Oilunkaniemi,S. R. Laitinen,M. AhlgrØn,
J. Organomet.
[14] I. Kamiya,E. Nishinaka,A. Ogawa, J. Org. Chem. 2005, 70,696 –
698.
Chem. 1999, 587,200 – 206.
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