1,4-Distanna-[4]ferrocenophanes by Pt(0)-catalysed distannation of alkynes

Article abstract of DOI:10.1016/S0022-328X(98)01028-6

1,1,2,2-Tetramethyl-1,2-distanna-[2]ferrocenophane 1 reacts with alkynes R-C≡CH [R = H (a), Me (b), ⁿPr (c), ⁿBu (d), ⁿPen (e), Ph (f), Me₃SiOCH² (g), Et(HO)CH (h), EtO(O)C (i)], in the presence of a catalytic amount of bis(triphenylphosphane)etheneplatinum 3, to give the 1,1,4,4-tetramethyl-1,4-distanna-[4]ferrocenophanes 4a-i by 1,2-distannation of the C≡C bond. The same products are obtained by the stoichiometric reaction of the alkynes with 1,1,3,3-tetramethyl-2,2-bis(triphenylphosphane)-1,2-distanna-3-platina-[3] ferrocenophane 2. This platinum(II) complex also reacts with cyclooctyne and dimethyl acetylene dicarboxylate to give the [4]ferrocenophanes 5 and 6, respectively. Thus, complex 2 must be considered as the active species in the Pt(0)-catalysed distannation of alkynes. The products were characterised by ¹H-, ¹³C- and ¹¹⁹Sn-NMR, using one- and two-dimensional techniques.

Full text of DOI:10.1016/S0022-328X(98)01028-6

Journal of Organometallic Chemistry 577 (1999) 76–81
1,4-Distanna-[4]ferrocenophanes by Pt(0)-catalysed distannation of
alkynes
Max Herberhold 1, Udo Steffl, Bernd Wrackmeyer *
Laboratorium fu¨r Anorganische Chemie der Uni6ersita¨t Bayreuth, Uni6ersita¨tsstr. 30, D-95440 Bayreuth, Germany
Received 30 July 1998; received in revised form 11 September 1998
Abstract
1,1,2,2-Tetramethyl-1,2-distanna-[2]ferrocenophane 1 reacts with alkynes R–CꢀCH [R=H (a), Me (b), nPr (c), nBu (d), nPen (e),
Ph (f), Me3SiOCH2 (g), Et(HO)CH (h), EtO(O)C (i)], in the presence of a catalytic amount of bis(triphenylphos-
phane)etheneplatinum 3, to give the 1,1,4,4-tetramethyl-1,4-distanna-[4]ferrocenophanes 4a–i by 1,2-distannation of the CꢀC
bond. The same products are obtained by the stoichiometric reaction of the alkynes with 1,1,3,3-tetramethyl-2,2-bis(triphenylphos-
phane)-1,2-distanna-3-platina-[3]ferrocenophane 2. This platinum(II) complex also reacts with cyclooctyne and dimethyl acetylene
dicarboxylate to give the [4]ferrocenophanes 5 and 6, respectively. Thus, complex 2 must be considered as the active species in the
Pt(0)-catalysed distannation of alkynes. The products were characterised by 1H-, 13C- and 119Sn-NMR, using one- and
two-dimensional techniques. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Ferrocene; Platinum; Tin; Distannation; Alkynes; NMR spectroscopy
In the present work we report on the reactions of 1
with alkynes in the presence of catalytic amounts of the
ethene complex 3 and of alkynes with a stoichiometric
amount of the 1,3-distanna-2-platina-[3]ferrocenophane
1. Introduction
Metal-catalysed addition of main group metal frag-
ments to CꢀC bonds [1,2] provides an elegant route to
novel reactive olefins which are difficult to prepare by
other methods. Distannation of many alkynes has been
shown to proceed under mild reaction conditions by
Pd(0) catalysis [3]. Recently we have obtained the 1,3-
distanna-2-platina-[3]ferrocenophane 2 [4] by oxidative
addition of the 1,2-distanna-[2]ferrocenophane 1 [5] to
the bis(triphenylphosphane)platinum(0) fragment (gen-
erated in situ from the ethene complex 3), as shown in
Scheme 1. The compound 2 can be readily converted
into other bis(phosphane) complexes [6], all of which
must be considered as the relevant intermediates in the
Pt(0)-catalysed distannation of alkynes [6,7], as re-
ported for 2 in a preliminary note [4].
1
2. H-, 13C- and 119Sn-NMR spectroscopy serve for the
structural characterisation of the products in solution.
2. Results and discussion
2.1. Distannation of terminal alkynes
It is shown in Scheme 1 that both the catalytic
(starting from 1) and the stoichiometric reaction (start-
ing from 2) afford the 1,4-distanna-[4]ferrocenophanes
4a–i. In the case of 4b, an isomer 4b% is also formed. In
the Pd(0)-catalysed reaction of hexamethyldistannane
with propyne, the isomer analogous to 4b% is the only
product [3b]. The attempt to catalyse the addition of 1
to both CꢀC bonds in 1,5-hexadiyne gave only a small
amount of the mono-addition product 4j which could
* Corresponding author. Tel.: +49-921-552542; fax: +49-921-
552157; e-mail: b.wrack@uni-bayreuth.de
1 Also corresponding author.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(98)01028-6

M. Herberhold et al. / Journal of Organometallic Chemistry 577 (1999) 76–81
77
terminal alkenes (1-nonene, cyclooctene, norbornene),
nor with dienes (norbornadiene). However, 2 reacts
smoothly with cyclooctyne to give 5. There was also a
reaction in the case of dimethyl acetylene dicarboxylate
and 2: the desired compound 6 is formed only as a side
product; the main reaction is trimerisation to give
hexamethyl benzene hexacarboxylate, C6(CO2Me)6.
2.3. NMR-spectroscopic results
The proposed structures of the new 1,4-distanna-
[4]ferrocenophanes are supported by the NMR spectro-
1
scopic data (Table 1). In most cases, the H- and/or
13C-NMR spectra are well resolved and show the rele-
vant signals accompanied by 117/119Sn satellite signals
according to coupling constants nJ(Sn, 1H) (n=2, 3)
and nJ(Sn, 13C) (n=1–4). The magnitude of these
coupling constants is typical of the cis-stannyl groups
at the CꢁC bond [3b, g, 8]. Similarly, the coupling
constants nJ(119Sn, 13Cferrocene) (n=1, 2, 3) are in the
expected range [4–6,9,10]. The 119Sn-NMR signals are
accompanied by 117Sn (AX spin system) and 119Sn
satellites (AB spin system) as the result of 3J(Sn, Sn). In
the case of the symmetric compounds 4a, 5 and 6, only
the 117Sn satellites are observed. The magnitude of these
coupling constants is in the same range as for compara-
ble bis(trimethylstannyl) derivatives [3b, g, 8], and the
changes induced by the various substituents are also
similar in trend and in magnitude [8]. A positive sign of
this coupling constant has been determined previously
[11] by 2D heteronuclear shift correlations of the type
119Sn/1H in which the positive tilt of the relevant cross
peaks [12] indicates alike signs of 3K(117Sn, 1H) and
3K(119Sn, 117Sn) (the reduced coupling constant K is
used because of k(119Sn) and k(117Sn)B0). Since the
former is known to be positive [13], it follows that
3K(119Sn, 117Sn)\0 [3J(119Sn, 117Sn)\0]. A similar ex-
periment is shown in Fig. 1, where the 13C/1H HET-
COR for the olefinic ꢁC–H unit reveals the relative and
Scheme 1.
not be separated from 1. There was no appreciable
reaction of 1 (in the presence of 3) with 1-alkynes
HCꢀCR bearing a more bulky substituent R (R=cy-
clopentyl, tBu, SiMe3, SnMe3). Although 1H-NMR
spectra prove the high purity of 4a–i, 5 and 6 (vide
infra), all products could be isolated only as yellow oils,
in spite of numerous attempts to obtain crystalline
material.
The use of other potential catalysts such as
Pt(PPh3)4, Pd(PPh3)4, Pd(dba)2 (dba=trans,trans-
dibenzylideneacetone) was not successful. If the cata-
absolute
signs
of
1J(119Sn, 13Cꢁ)B0
and
lytic activity of
3 would depend not only on
2J(119Sn, ꢁ13C)B0.
dissociation of ethene from the Pt(0) centre but also on
the cleavage of one of the Pt–P bonds, the presence of
an excess of PPh3 should have an effect. However, the
yield of 4 did not change under such conditions (PPh3
and 3 in a 1:1 ratio). It was found that the complex 2
and also its dppe congener [6] are active catalysts in the
reactions leading to 4. Therefore, it appears to be a safe
assumption that 2 is indeed the important intermediate
in the described Pt(0)-catalysed distannation of alkynes.
3. Conclusions
The new class of [4]ferrocenophanes described here is
conveniently accessible from the 1,2-distanna-
[2]ferrocenophane 1 by Pt(0)-catalysed distannation of
terminal alkynes bearing non-bulky substituents. Since
the same compounds could be prepared from the plat-
inum complex 2 in stoichiometric reactions, 2 must be
regarded as the active species in the Pt(0)-catalysed
reactions. The reactivity of the Sn–C bonds [14] in the
new [4]ferrocenophanes is of interest for further trans-
formations, in particular with respect to the influence of
the ferrocenediyl unit.
2.2. Distannation of non-terminal alkynes and attempts
at the distannation of alkenes and dienes
There was no reaction of 1 (in the presence of 3) with
unstrained or non-activated non-terminal alkynes (3-
hexyne and diphenylethyne), or with terminal and non-

78
M. Herberhold et al. / Journal of Organometallic Chemistry 577 (1999) 76–81
Table 1
1H-, 13C- and 119Sn-NMR dataa of the 1,4-distanna-[4]ferrocenophanes 4a–j, 5 and 6
No
l1H
l
13C
l
119Sn
H(2,5)
H(3,4)
SnMe2
other
C(1)
C(2,5)
C(3,4)
SnMe2
other
4a
4b
4.06
[10.6]
4.25
[6.1]
0.29
[54.9]
7.43
[204.6] [131.8]
66.7
[499.7]
[2.0]
74.7
[52.8]
71.5
[41.1]
-8.0
[356.2]
154.9 (ꢁCH)
−71.4
[444.2]
[528.2] [31.7]
4.06
4.06
4.26
4.26
4.25
4.26
4.26
4.24
4.25
4.30
0.30
[54.8]
0.24
6.81 (ꢁCH)
[204.8] [102.0]
2.17 (ꢁCMe)
[49.7][10.6]
67.3
[494.6]
[2.0]
67.0
[496.4]
[2.4]
75.0
[51.2]
74.9
71.44
[40.2]
71.38
[40.2]
−7.7
[340.1]
−7.9
144.1 (ꢁCH)
[556.9] [73.0]
163.4 (ꢁC)
[544.8] [34.8]
33.9 (Me)
−73.1
[349.2]
−61.5
[349.2]
[53.5]
[50.1]
[356.4]
[113.4] [86.1]
4b%
4c
4d
4e
4f
0.31
[53.5]
0.29
5.08 (ꢁCH)
[80.1] [27.3]
5.66 (ꢁCH)
[166.4] [25.9]
2.30 (SnCH2)
[70.9]
67.8
[471.4]
67.1
74.7
[53.4]
74.6
71.3
[40.2]
71.2
−9.1
[362.9]
−9.2
120.7 (ꢁCH2)
[49.0] [40.2]
152.7 (ꢁC)
[518.8] [54.5]
25.2 (SnCH2)
[324.6] [55.6]
−40.1
[96.9]
−17.9
[96.9]
[54.2]
[484.3]
[51.2]
[40.2]
[347.4]
4.07
[10.4]
0.34
[54.1]
0.31
6.80 (ꢁCH)
[205.8] [102.6]
2.42 (ꢁC–CH2)
[56.6][5.6]
1.46, 0.92
(CH2CH3)
67.3
[484.0]
67.0
[2.0]
[496.4]
[2.4]
74.7
[54.0]
74.5
71.4
[41.0]
71.3
−7.4
[338.6]
−7.6
143.5 (ꢁCH)
[547.0] [71.6]
159.7 (ꢁC)
[518.2] [36.4]
49.7 (CH2)b
[101.5] [75.7]
−72.7
[362.2]
−62.4
[362.2]
[54.7]
[52.8]
[38.7]
[357.4]
4.08
0.36
[54.1]
0.31
6.81 (ꢁCH)
67.8
[484.3]
[2.0]
67.2
[499.8]
[1.8]
75.0
[53.4]
74.5
71.4
[40.4]
71.3
−7.3
[337.9]
−7.6
143.2 (ꢁCH)
[551.5] [73.0]
169.2 (ꢁC)
[524.8] [30.5]
47.4 (CH2)c
[102.5] [76.3]
−72.5
[313.5]
−62.4
[313.3]
[206.1] [101.9]
2.46 (ꢁC–CH2)
[54.7] [6.2]
1.0–1.4, 0.9
[(CH2)2CH3]
[54.7]
[52.4]
[40.4]
[356.4]
4.08
[10.6]
0.36
[52.8]
0.34
6.83 (ꢁCH)
67.9
[484.6]
[2.0]
67.3
[498.0]
[2.0]
74.6
[54.0]
74.4
71.4
[39.9]
71.3
−7.1
[341.6]
−7.3
143.2 (ꢁCH)
[547.0] [72.8]
169.2 (ꢁC)
[516.4] [36.8]
42.7 (CH2)d
[101.5] [75.7]
−72.4
[341.7]
−62.5
[341.7]
[207.0] [102.6]
2.47 (ꢁC–CH2)
[56.6] [5.6]
0.9–1.3, 0.87
[(CH2)3CH3]
[54.2]
[52.8]
[41.0]
[356.8]
4.10
4.09
0.33
[54.8]
0.29
6.98 (ꢁCH)
[205.8] [98.4]
7.10–7.40 (Ph)
67.9
[480.0]
67.0
74.5
[53.7]
74.3
71.04
[41.6]
71.03
[41.6]
−6.4
[358.3]
−7.3
149.0 (ꢁCH)
[123.0] [65.0]
173.5 (ꢁC)
−66.7
[308.9]
−56.6
[308.9]
[54.8]
[498.3]
[52.9]
[365.2]
[507.4] [37.1]
e
149.8 (Cipso
)
[101.1] [62.4]
4g
4h
0.44
[54.7]
0.31
7.01 (ꢁCH)
[202.0] [94.7]
4.33 (CH2O)
[48.2] [9.0]
66.4
[465.0]
[1.8]
66.2
[456.0]
[1.8]
75.2
[52.8]
74.8
71.7
[41.0]
71.6
−6.6
[359.2]
−7.6
140.8 (ꢁCH)
[538.8] [64.6]
168.2 (ꢁC)
[510.6] [35.2]
68.4 (CH2O)f
[128.6] [62.0]
−66.1
[347.9]
−64.4
[347.9]
[54.4]
[51.6]
[41.0]
[361.5]
0.11 (SiMe3)
4.11
4.09
0.50
[56.0]
0.48
[56.0]
0.35
[54.8]
0.31
6.80 (ꢁCH)
[201.6] [99.8]
4.0 (CHO)
[50.2] [6.0]
2.50 (OH)
1.61, 0.92
68.8
[474.2]
[1.8]
68.6
[472.6]
[1.8]
74.7
[50.0]
74.7
[52.8]
74.65
[54.1]
71.4
−5.1
[359.2]
−5.7
[359.2]
−7.39
[359.2]
−7.43
[359.2]
140.5 (ꢁCH)
[539.6] [65.2]
173.5 (ꢁC)
[545.8] [29.2]
85.2 (CHO)
[106.8] [56.8]
30.7, 10.5
−68.3
[380.6]
−67.1
[380.6]
[43.0]
71.26
[47.5]
71.23
[47.5]
(CH2CH3)
[54.8]
(CH2CH3)

M. Herberhold et al. / Journal of Organometallic Chemistry 577 (1999) 76–81
79
Table 1 (continued)
No
l1H
l
13C
l
119Sn
H(2,5)
4.06
H(3,4)
4.25
SnMe2
other
C(1)
C(2,5)
C(3,4)
SnMe2
other
4i
0.23
[52.6]
0.26
3.32, 1.08
(OCH2CH3)
68.0
[432.6]
68.4
74.5
[54.1]
74.3
71.0
[42.7]
70.9
−6.8
[355.8]
−7.0
[346.8]
[346.8]
140.5 (ꢁCH)
[498.0] [56.2]
168.2 (ꢁC)
[475.5] [44.2]
165.2 (CꢁO)
[98.6] [45.7]
60.1, 14.5
−58.5
[294.0]
−54.2
[294.0]
[52.8]
[442.6]
[52.8]
[42.3]
(OCH2CH3)
4j
4.08
4.27
0.28
[52.3]
0.23
6.80 (ꢁCH)
[200.5] [103.4]
2.6 (CH2)
[51.2] [7.4]
2.2, 2.5
(CH2CH2)
1.8 (ꢀCH)
68.0
[456.3]
68.0
74.3
[54.0]
74.0
70.9
−7.6
[358.2]
−6.8
144.8 (ꢁCH)
[542.0] [69.8]
162.0 (ꢁC)
[508.6] [42.4]
45.4 (CH2)
[101.2] [72.8]
72.9, 66.8
−78.7
[352.0]
−71.7
[352.0]
[41.0]
70.95
[41.9]
[52.0]
[456.3]
[53.6]
[361.5]
(CꢀCH)
5
6
4.06
[10.7]
4.26
4.28
0.33
[51.6]
2.6 (CH2)
[69.8] [6.2]
1.5 [(CH2)4]
68.0
[468.9]
[2.0]
74.5
[52.8]
71.3
[39.5]
−6.7
[334.3]
158.3 (ꢁC)
[572.9] [63.8]
33.7 (CH2)
[86.7] [73.8]
29.2 (CH2)
[13.6] [6.2]
26.6 (CH2)
−63.3
[488.3]
4.05
0.23
[54.2]
3.33 (OCH3)
68.2
[465.3]
74.7
[54.4]
70.8
[42.5]
−6.5
[360.2]
160.2 (ꢁC)
−35.7
[309.9]
[475.5] [44.2]
165.2 (CꢁO)
[102.4] [49.8]
56.8 (OMe)
n
n
n
a In C6D6 at room temperature; coupling constants J(119Sn, 1H) (90.5 Hz), J(119Sn, 13C) (91 Hz), and J(119Sn, 117Sn) (91.5 Hz) are given
in brackets.
b l13C=23.5 [11.7], 13.8 (CH2CH3).
c l13C=32.7 [9.8], 22.6, 14.2 (CH2CH2CH3).
d l13C=30.3 [11.7], 23.0, 23.0, 14.2 (CH2CH2CH2CH3).
e l13C=130.3 (Cortho), 128.0 (Cmeta), 126.1 (Cpara).
f l13C=−0.3 (Me3Si).
4. Experimental
(C6D5H)=7.14, (C6D5CD2H)=2.03; l13C (CDCl3)=
77.0, (C6D6)=128.0, (C6D5CD3)=20.4], and Me4Sn
[l119Sn=0 for ] (119Sn)=37.290665 MHz].
4.1. General
All compounds were handled in an atmosphere of
dry argon, and carefully dried solvents were used for
syntheses and the preparation of the samples for NMR
measurements. Starting materials were either used as
commercial products without further purification (all
alkynes, alkenes and dienes) or prepared as described (1
[5], 2 [4], 3 [15]). Electron impact (EI) mass spectra:
Finnigan MAT 8500 with direct inlet (the isotope distri-
bution in calculated mass spectra is in agreement with
the experimental spectra). NMR measurements: Bruker
4.2. 1,1,4,4-Tetramethyl-1,4-distanna-[4]ferrocenophanes
4, 5, 6: general procedures, starting from 1 with
catalyst 3, or from 2
A THF solution (30 ml) containing 1 (0.12 g; 0.25
mmol), the alkyne (0.3 mmol) and 3 (0.0025 mmol) (30
ml) is heated at reflux for 72 h. In the cases of 4a,b, ethyne
and propyne, respectively, were introduced into the
boiling THF solution containing 1 and 3, and the reaction
wascompleteafter4–5h.Thesolventisremovedinvacuo,
and the residue is extracted with hexane. After filtration,
chromatography of the solution on silica and elution with
hexane affords the products 4a–i as orange oils.
1
ARX 250 or DRX 500; H-, 13C-, 119Sn-NMR (mea-
1
sured either directly using inverse gated H decoupling
2
or by refocused INEPT [16], based on J(119Sn, 1H)=
1
55 Hz, with H decoupling). Chemical shifts are given
Therespectivealkyne(0.15mmol)isaddedtoasolution
of the complex 2 (0.12 g; 0.1 mmol) in THF (30 ml), and
with respect to Me4Si [l1H (CHCl3/CDCl3)=7.24,

80
M. Herberhold et al. / Journal of Organometallic Chemistry 577 (1999) 76–81
4I
5
yield 13%; C19H26FeO2Sn2, EI-MS: m/e
(%)=579 (20) [M+], 469 (100)
[Fe(C5H4)2Sn2Me+3 ]
yield 97%; C22H32FeSn2, EI-MS: m/e
(%)=589 (60) [M+], 469 (100)
[Fe(C5H4)2Sn2Me+3 ]
6
yield 11%; C22H30FeO4Sn2, EI-MS: m/e
(%)=623 (100) [M+]
Acknowledgements
We gratefully acknowledge support of this work by
the Deutsche Forschungsgemeinschaft and the Fonds
der Chemischen Industrie.
References
[1] (a) J.K. Kochi, Organometallic Mechanism and Catalysis, Aca-
demic Press, New York, 1978. (b) R.F. Heck, Palladium
Reagents in Organic Synthesis, Academic Press, New York,
1985. (c) H. Watanabe, M. Kobayashi, M. Saito, Y. Nagai, J.
Organomet. Chem. 215 (1991) 149. (d) N. Miyaura, A. Suzuki,
Chem. Rev. 95 (1995) 2457.
[2] (a) T.N. Mitchell, R. Wickenkamp, A. Amamria, R. Dicke, U.
Schneider, J. Org. Chem. 52 (1987) 4868. (b) B.L. Chenard, C.M.
van Zyl, J. Org. Chem. 51 (1986) 3561. (c) M. Murakami, Y.
Morita, Y. Ito, J. Chem. Soc. Chem. Commun. (1990) 428. (d)
W. Finckh, B.-Z. Tang, A.J. Lough, I. Manners, Organometal-
lics, 11 (1992) 2904.
Fig. 1. Contour plot of the 2D 125.8 MHz 13C/1H HETCOR (based
on 1J(ꢁ13C, 1H)) of the olefinic carbon atom of 4d. The positive tilt of
all cross peaks for the 117/119Sn satellites shows that 1K(Sn, 13Cꢁ),
2K(Sn, ꢁ13C), 2K(Sn, 1H) and 3K(Sn, 1H) have the same sign (all
positive, since 2/3K(Sn, 1H)\0 [13]).
.
[3] (a) E. Piers, R.T. Skerjl, J. Chem. Soc. Chem. Commun. (1986).
(b) T.N. Mitchell, A. Amamria, H. Killing, D. Rutschow, J.
Organomet. Chem. 304 (1986) 257. (c) T.N. Mitchell, U.
Schneider, J. Organomet. Chem. 407 (1991) 319. (d) H. Killing,
T.N. Mitchell, Organometallics, 3 (1984) 1017. (e) T.N. Mitchell,
N.M. Dornseifer, A. Rahm, J. High. Press. Res. 7 (1991) 165. (f)
T.N. Mitchell, G. Kowall, J. Organomet. Chem. 437 (1992) 127.
(g) M. Niestroj, W.P. Neumann, T.N. Mitchell, J. Organomet.
Chem. 519 (1996) 45.
[4] M. Herberhold, U. Steffl, W. Milius, B. Wrackmeyer, Angew.
Chem. 107 (1997) 1545; Angew. Chem. Int. Ed. Engl. 36 (1997)
1510.
[5] M. Herberhold, U. Steffl, W. Milius, B. Wrackmeyer, Angew.
Chem. 108 (1996) 1927; Angew. Chem. Int. Ed. Engl. 35 (1996)
1803.
[6] M. Herberhold, U. Steffl, W. Milius, B. Wrackmeyer, Chem.
Eur. J. 4 (1998) 1027.
[7] (a) Y. Obora, Y. Tsuji, K. Nishiyama, M. Ebihara, T. Kawa-
mura, J. Am. Chem. Soc. 118 (1996) 10922. (b) Y. Tsuji, K.
Nishiyama, S. Hori, M. Ebihara, T. Kawamura, Organometal-
lics, 17 (1998) 507.
[8] B. Wrackmeyer, K. Wagner, Chem. Ber. 122 (1989) 857.
[9] F.H. Ko¨hler, W.A. Geike, N. Hertkorn, J. Organomet. Chem.
334 (1987) 359.
[10] (a) M. Herberhold, U. Steffl, W. Milius, B. Wrackmeyer, J.
Organomet. Chem. 533 (1997) 109. (b) M. Herberhold, U. Steffl,
W. Milius, B. Wrackmeyer, Z. Anorg. Allg. Chem. 624 (1998)
386. (c) M. Herberhold, W. Milius, U. Steffl, K. Vitzithum, W.
Milius, B. Wrackmeyer, R.H. Herber, M. Fontani, P. Zanello,
Eur. J. Inorg. Chem., in press.
the mixture is heated at reflux for 72 h (4–5 h for 4a,b).
The products 4a–i are obtained in similar yield as
described above. Furthermore, the compounds 5 and 6
are isolated by the stoichiometric reaction as orange
oils. In the case of 5, the reaction starts instanta-
neously.
4a
yield 87%; C16H22FeSn2, EI-MS: m/e
(%)=507 (100) [M+]
4b, 4b%
4c
yield 50%; C17H24FeSn2, EI-MS: m/e
(%)=521 (100) [M+]
yield 45%; C19H28FeSn2, EI-MS: m/e
(%)=549 (70) [M+], 469 (100)
[Fe(C5H4)2Sn2Me+3 ]
4d
4e
4f
yield 56%; C20H30FeSn2, EI-MS: m/e
(%)=563 (70) [M+], 469 (100)
[Fe(C5H4)2Sn2Me+3 ]
yield 31%; C21H32FeSn2, EI-MS: m/e
(%)=577 (40) [M+], 303 (100)
[Fe(C5H4)2Sn+]
yield 54%; C22H26FeSn2, EI-MS: m/e
(%)=577 (80) [M+], 469 (100)
[Fe(C5H4)2Sn2Me+3 ]
4g
4h
yield 67%; C20H32FeOSiSn2, EI-MS: m/e
(%)=609 [M+]
[11] B. Wrackmeyer, K. Wagner, unpublished results.
[12] (a) A. Bax, R. Freeman, J. Magn. Reson. 45 (1981) 177. (b) B.
Wrackmeyer, K. Horchler, Magn. Reson. Chem. 28 (1990) 56.
yield 64%; C19H28FeOSn2, EI-MS: m/e
(%)=565 (100) [M+]

M. Herberhold et al. / Journal of Organometallic Chemistry 577 (1999) 76–81
[13] V.S. Petrosyan, Prog. NMR Spectrosc. 11 (1977) 115. [15] U. Nagel, Chem. Ber. 115 (1982) 1948.
81
[14] (a) M. Pereyre, J.-P. Quintard, A. Rahm, Tin in Organic
Synthesis, Butterworths, London, 1987. (b) A.G. Davies,
Organotin Chemistry, VCH, Weinheim, 1997.
[16] (a) G.A. Morris, R. Freeman, J. Am. Chem. Soc. 101 (1979) 760.
(b) G.A. Morris, J. Am. Chem. Soc. 102 (1980) 428. (c) D.P.
Burum, R.R. Ernst, J. Magn. Reson. 39 (1980)163.
.