Reaction of β-diketiminate tin(ii) dimethylamide LSnNMe2 [L = HC(CMeNAr)2; Ar = 2,6-iPr2C6H3] with ketones and alkynes

Article abstract of DOI:10.1039/c002849e

The reactions of stable β-diketiminate tin(ii) dimethylamide LSnNMe₂ [L = HC(CMeNAr)₂; Ar = 2,6-iPr₂C ₆H₃] (1) with ketones and activated terminal alkynes are described. 1 reacts with 2-benzoylpyridine and 2,2,2-trifluoroacetophenone to give the tin(ii)-alkoxides LSnOCPh(2-Py)NMe₂ (2) and LSnOCPh(CF ₃)NMe₂ (3), respectively, by nucleophilic addition of the dimethylamido group to the carbonyl moiety. Furthermore, the reaction of 1 with terminal alkynes (HCCCO₂R, R = Me, Et) forms tin(ii)-alkynyl LSnCCCO₂R (R = Me, (4); R = Et, (5)) compounds under elimination of Me₂NH rather than undergoing a nucleophilic addition reaction at the carbon-carbon triple bond. Compounds 2-5 were characterized by microanalysis and multinuclear NMR spectroscopy. Moreover, 2 and 5 could be crystallized and their constitutions were confirmed by X-ray structural analysis. 2 and 5 are monomers in the solid state and the metal atom shows a distorted trigonal-pyramidal coordination sphere.

Full text of DOI:10.1039/c002849e

View Article Online / Journal Homepage / Table of Contents for this issue
PAPER
www.rsc.org/dalton | Dalton Transactions
Reaction of b-diketiminate tin(II) dimethylamide LSnNMe2
[L = HC(CMeNAr)2; Ar = 2,6-iPr2C6H3] with ketones and alkynes†‡
Anukul Jana, Ina Objartel, Herbert W. Roesky* and Dietmar Stalke
Received 11th February 2010, Accepted 23rd March 2010
First published as an Advance Article on the web 19th April 2010
DOI: 10.1039/c002849e
The reactions of stable b-diketiminate tin(II) dimethylamide LSnNMe2 [L = HC(CMeNAr)2; Ar =
2,6-iPr2C6H3] (1) with ketones and activated terminal alkynes are described. 1 reacts with 2-benzoyl-
pyridine and 2,2,2-trifluoroacetophenone to give the tin(II)-alkoxides LSnOCPh(2-Py)NMe2 (2) and
LSnOCPh(CF3)NMe2 (3), respectively, by nucleophilic addition of the dimethylamido group to the
carbonyl moiety. Furthermore, the reaction of 1 with terminal alkynes (HCCCO2R, R = Me, Et) forms
tin(II)-alkynyl LSnCCCO2R (R = Me, (4); R = Et, (5)) compounds under elimination of Me2NH rather
than undergoing a nucleophilic addition reaction at the carbon–carbon triple bond. Compounds 2–5
were characterized by microanalysis and multinuclear NMR spectroscopy. Moreover, 2 and 5 could be
crystallized and their constitutions were confirmed by X-ray structural analysis. 2 and 5 are monomers
in the solid state and the metal atom shows a distorted trigonal-pyramidal coordination sphere.
instead of toluene and obtained 1 in excellent yield by the reaction
Introduction
of LSnCl with LiNMe2 in a 1 : 1 ratio. The spectroscopic data
match with previously reported values.5 It is worth mentioning
that recently we reported the synthesis of LGeNH2 by the reaction
The chemistry of compounds with low valent group 14 ele-
ments, namely carbenes, silylenes, germylenes, stannylenes, and
plumbylenes has received considerable attention in recent years,
due to some special properties and reactivities.1 Recently we
showed that “H”-transfer was successful to a variety of un-
saturated compounds by using germanium(II) hydride, LGeH2
and tin(II) hydride, LSnH,3 respectively, at room temperature
without adding any catalyst [L = HC(CMeNAr)2; Ar = 2,6-
iPr2C6H3]. Now we became interested in transferring the “NMe2”
residue to unsaturated organic molecules to synthesize the nitrogen
containing compounds. The latter play an important role in many
biologically active systems as well as in organic targets, new
materials, and fine chemicals.4 Here we selected the stable tin(II)
amido compound LSnNMe2 (1)5 as a starting material.
1
1
=
of L Ge [L = HC{(C CH2)(CMe)(NAr)2; Ar = 2,6-iPr2C6H3]
with NH3.10
The insertion reaction of carbonyl compounds into the metal–
nitrogen bond has been known for lanthanides and for transition
metal complexes.11 However, the insertion of the carbon–oxygen
bond into the metal–nitrogen bond has not been well studied
with main group compounds. This may be due to the poor
reactivity of compounds with nitrogen bonds, although last year
our group reported the addition of dimethylaminobismuth to
aldehydes, ketones, alkenes, and alkynes.12 Lappert and co-
workers described the addition of aminostannanes to a variety
of alkynes and alkenes and also aminosilylation and aminophos-
phination reactions with highly electrophilic substrates.13 Re-
cently, Hartwig and co-workers reported transammination of
alkenes and vinylarenes by rhodium(I) amides.14 The insertion
of an alkyne into a molybdenum–amide bond has also been
described.15
Results and discussion
After the preparation of the monomeric b-diketiminate stabilised
heteroleptic tin(II) chloride LSnCl6 it turned out to be the right
starting material for the preparation of stannylenes LSnX with
small terminal substituents X = H,3a,7 Me,8 F.8 Hetero-bimetallic
compounds with direct metal–metal bonds are accessible in
nucleophilic substitution reactions.9 In 2006 Gibson and co-
workers reported the synthesis of LSnNMe2 (1) and studied
the mechanistic properties of single-site b-diketiminate tin(II)
initiators for polymerization of rac-lactide.5 Herein we describe
the preparation of LSnNMe2 (1) using diethyl ether as a solvent
The carbonyl group and its transformation to other functional
groups is very important in organic chemistry.16 Up to now there
are no reports in the literature of reactions with tin(IV) amide and
carbonyl compounds.
Treatment of 1 with 2-benzoylpyridine and 2,2,2-trifluoro-
acetophenone leads almost quantitatively to the stannylene alko-
xides 2 and 3, respectively (Scheme 1) with formation of the
Sn–O–CNMe2 core. The 1H NMR spectrum of 2 exhibits a
singlet (d 4.92 ppm) which can be assigned to the g -CH proton
and a singlet resonance at d 1.83 ppm for the NMe2 group.
The four isopropyl groups of 2 are exhibiting four different
resonances, and even the two methyl groups in the backbone show
two different signals in the proton NMR spectrum. The 119Sn
NMR resonance of 2 arises at d -328 ppm. 2 crystallizes in the
Institut fu¨r Anorganische Chemie, Universita¨t Go¨ttingen, Tammannstrasse
4, 37077, Go¨ttingen, Germany. E-mail: hroesky@gwdg.de; Fax: +49-551-
393373
† Dedicated to Professor Hubert Schmidbaur on the occasion of his 75th
birthday.
‡ CCDC reference numbers 743154 and 743155 for 2 and 5 respectively.
For crystallographic data in CIF or other electronic format see DOI:
10.1039/c002849e
¯
triclinic space group P1 with one monomer in the asymmetric unit
(Fig. 1).
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 4647–4650 | 4647
©

View Article Online
reaction there is no sign that some side products are formed by
nucleophilic addition of LSnNMe2 (1) to the carbon–carbon triple
bond, which we observed exclusively in the case of LGeH2 and
LSnH3 when they were reacted with terminal alkynes.
In the 1H NMR spectra of 4 and 5, the complete disappearance
of the proton resonance of Sn–NMe2 was observed. This indicates
the total conversion of the tin amide to the corresponding tin-
alkynyl compounds.
Compounds 4 and 5 are yellow solids soluble in benzene, THF,
n-hexane, and n-pentane, respectively and show no decomposition
on exposure to air. 4 and 5 were characterized by multinuclear
NMR and IR spectroscopy, EI mass spectrometry, and elemental
analysis. Furthermore, 5 could be characterized by single crystal
X-ray structural analysis (Fig. 2). 5 crystallizes in the monoclinic
space group P21/n with one monomer in the asymmetric unit,
and with four molecules in each unit cell. Single crystals were
obtained after two days from a saturated n-hexane solution in a
freezer at -30 ◦C (Table 1). The coordination polyhedron around
the tin atom features a distorted tetrahedral geometry with a
Fig. 1 Molecular structure of 2. Anisotropic displacement parameters
1
are depicted at the 50% probability level. All hydrogen atoms are omitted
stereochemically active lone pair. The H NMR spectrum of 5
◦
˚
for clarity. Selected bond lengths [A] and angles [ ]: Sn1–O1 2.0505(11),
Sn1–N1 2.2538(13), Sn1–N3 2.5580(14), O1–C43 1.3907(19); N1–Sn1–N2
83.14(5), N1–Sn1–O1 102.50(5), Sn1–O1–C43 125.03(10).
shows a quartet and a triplet resonance (d 3.92 and 0.92 ppm)
corresponding to the two different types of CH protons of the
ethyl moiety.
Scheme 1 Preparation of compounds 2 and 3.
1
Compound 3 has one CF3 group and the H NMR spectrum
exhibits a quartet (d 5.15 ppm) which corresponds to the
quaternary CH proton. The 19F NMR resonance arises as a singlet
(d -69.74 ppm) and is flanked by 119Sn satellite lines (4J(119Sn,19F) =
129 Hz). The 119Sn NMR resonance of 3 arises as a quartet at
4
d -232 ppm with the same coupling constant of J(119Sn,19F) =
129 Hz. The two 119Sn NMR values of 2 and 3 are different due to
the contrasting substituents of R.
After the successful reaction of 1 with ketones, we subsequently
Fig. 2 Molecular structure of 5. Anisotropic displacement parameters
are depicted at the 50% probability level. All hydrogen atoms are omitted
≡
treated 1 with alkynes. Compound 1 reacts with HC CCO2Me
◦
˚
for clarity. Selected bond lengths [A] and angles [ ]: Sn1–N1 2.1802(16),
Sn1–C1 2.214(2), C1–C2 1.213(3); C2–C3 1.447(3), C3–O1 1.208(3),
C3–O2 1.343(3); N1–Sn1–N2 86.33(6), N1–Sn1–C1 89.90(7), Sn1–C1–C2
168.83(19), C1–C2–C3 176.9(2).
≡
and HC CCO2Et, at room temperature in quantitative yield to
the alkynyl linked stannylenes 4 and 5, respectively, with a Sn(II)–
≡
C C framework that is formed by elimination of Me2NH due to
the different polarized Sn–NMe2 and C–H bonds (Scheme 2). The
1
reactions of 4 and 5 were monitored by their H NMR spectra.
1
Sharp resonances in the H NMR of 4 and 5 indicate that the
Experimental section
products have been formed in high yield. In the course of the
General considerations
All manipulations were performed in a dry and oxygen-free
atmosphere (N2) by using Schlenk-line and glove-box techniques.
Solvents were purified with the M-Braun solvent drying system.
Compound LSnCl was prepared by literature procedure.6 Other
chemicals were purchased and used as received. 1H, 19F, and 119Sn
NMR spectra were recorded on a Bruker Avance DRX instrument
1
Scheme 2 Preparation of compounds 4 and 5.
4648 | Dalton Trans., 2010, 39, 4647–4650
and referenced to the deuterated solvent in the case of the H
This journal is
The Royal Society of Chemistry 2010
©

View Article Online
Table 1 Crystal data for complexes 2 and 5
3.79 (sept, 1H, CH(CH3)2), 3.66 (sept, 1H, CH(CH3)2), 3.32
(sept, 1H, CH(CH3)2), 1.86 (s, 6H, N(CH3)2), 1.79 (s, 3H, CH3),
1.72 (s, 3H, CH3), 1.56 (d, 6H, CH(CH3)2), 1.31–1.11 (m, 15H,
2
5
Empirical formula
CCDC-No.
C43H56N4OSn
743154
C34H46N2O2Sn
743155
1
CH(CH3)2), -0.12 (d, 3H, CH(CH3)2) ppm. 119Sn { H} NMR
(186.50 MHz, C6D6): d -328 ppm. EI-MS: m/z (%) 537 (100) [M-
OCPh(2-Py)NMe2]+. Found C, 67.79; H, 7.96; N, 7.24. Calcd. for
C43H56N4OSn (764.35): C, 67.63; H, 7.39; N, 7.34.
Temperature
Crystal system
Space group
100(2) K
Triclinic
P1
11.0083(9)
11.8819(10)
16.971(2)
96.9270(10)
101.1180(10)
113.0550(10)
1956.3(3)
100(2) K
Monoclinic
P21/n
12.777(2)
19.911(4)
13.186(2)
90
104.998(2)
90
3240.2(10)
4
¯
˚
a/A
Synthesis of [{HC(CMeNAr)2}SnOC(NMe2)PhCF3] (Ar =
2,6-iPr2C6H3) (3). A solution of 2,2,2-trifluoroacetophenone
(0.175 g, 1.00 mmol in 5 mL toluene) was added by cannula to
a solution of 1 (0.54 g, 1.00 mmol in toluene 20 mL) at room
temperature. After 12 h all volatiles were removed in vacuum, and
the remaining residue was extracted with n-hexane (25 mL). The
solvent was removed an◦d compound 3 obtained as a powder. Yield:
0.550 g (73%); mp 178 C. 1H NMR (200 MHz, C6D6): d 7.32 (d,
2H, o-Ph-H), 7.08–7.17 (m, 6H, Ar-H), 7.00 (m, 3H, p-Ph-H, m-
Ph-H), 4.66 (s, 1H, g -CH), 3.99 (sept, 2H, CH(CH3)2), 3.14 (sept,
2H, CH(CH3)2), 1.99 (s, 6H, N(CH3)2), 1.59 (s, 3H, CH(CH3)2),
1.55 (s, 3H, CH3), 1.53 (s, 3H, CH3), 1.51 (d, 3H, CH(CH3)2),
1.12–1.27 (m, 15H, CH(CH3)2), 1.14 (d, 6H, CH(CH3)2) ppm.
˚
b/A
˚
c/A
a (◦)
b (◦)
g (◦)
3
˚
V/A
Z
2
rc/Mg m-3
1.296
0.690
800
1.298
0.819
1320
m/mm-1
F(000)
Crystal Size/mm
0.3/0.05/0.05
2.08-26.02
42763/7688
[R(int) = 0.0233]
7688/0/454
0.0200/0.0474
0.0232/0.0484
1.066
0.1/0.1/0.05
1.90-26.73
60564/6864
[R(int) = 0.0313]
6864/0/363
0.0249/0.0564
0.0307/0.0592
1.068
q range [◦]
Reflections
Collected/independent
Data/restraints/parameters
R1, wR2 [I > 2s(I)]a
R1, wR2 (all data)a
GoF
1
119Sn { H} NMR (186.50 MHz, C6D6): d -232 ppm. EI-MS: m/z
(%) 537 (100) [M-OCPh(CF3)NMe2]+. Found C, 61.55; H, 6.67;
N, 5.47. Calcd. for C39H52F3N3OSn (755.31): C, 62.08; H, 6.95; N,
5.57.
Residual density
max./min./e A
0.326, -0.250
0.942, -0.706
-3
˚
ꢀ
ꢀ
ꢀ
ꢀ
a R1 = ꢀFo| - |Fcꢀ/ |Fo|. wR2 = [ w(Fo - Fc2)2/ w(Fo2)2]0.5
.
2
Synthesis of [{HC(CMeNAr)2}SnCCCO2Me] (Ar
=
2,6-
iPr2C6H3) (4). A solution of HCCCO2Me (0.085 g, 1.00 mmol
in 5 mL toluene) was added drop by drop by cannula to a solution
of 1 (0.540 g, 1.00 mmol in toluene 15 mL) at room temperature.
After 0.5 h under constant stirring at ambient temperature all
volatiles were removed in vacuum, and the remaining residue was
extracted with n-hexane (15 mL) and concentrated to about 5 mL
NMR spectrum. 19F and 119Sn NMR spectra were referenced to
CFCl3 and SnMe4. Elemental analyses were performed by the
Analytisches Labor des Instituts fu¨r Anorganische Chemie der
Universita¨t Go¨ttingen. Mass spectra were obtained on a Finnigan
Mat 8230 instrument. Melting points were measured in a sealed
glass tube.
◦
and stored in a freezer at -30 C. After two days yellow crystals
of 4 are formed. Yield: 0.545 g (88%); mp 124 ◦C. 1H NMR
(300 MHz, C6D6): d 7.03–7.16 (m, 6H, Ar-H), 4.98 (s, 1H, g -CH),
3.88 (sept, 2H, CH(CH3)2), 3.29 (s, 3H, CO2CH3), 3.23 (sept, 2H,
CH(CH3)2), 1.58 (s, 6H, CH3), 1.47 (d, 6H, CH(CH3)2), 1.36 (d,
6H, CH(CH3)2), 1.21 (d, 6H, CH(CH3)2), 1.08 (d, 6H, CH(CH3)2)
Synthesis of [{HC(CMeNAr)2}SnNMe2] (Ar = 2,6-iPr2C6H3)
(1). A solution of LSnCl (0.498 g, 1.0 mmol) in diethyl ether
(20 mL) was added drop by drop to a stirred suspension of LiNMe2
(0.051 g, 1.0 mmol) in diethyl ether (10 mL) at -78 ◦C. The reaction
mixture was warmed to room temperature and was stirred for
another 12 h. The precipitate was filtered off, and the solvent was
partially reduced (ca. 20 mL). Storage of the remaining solution
in a freezer at -30 ◦C overnight afforded yellow crystals. Yield:
1
ppm. 119Sn { H} NMR (111.92 MHz, C6D6): d -254.91 ppm.
EI-MS: m/z (%) 620 (85) [M]+, 562 (100) [M-Me-iPr]+. Found
C, 63.28; H, 7.51; N, 4.73. Calcd. for C33H44N2O2Sn (620.24): C,
63.99; H, 7.16; N, 4.52.
1
0.533 g (92%). H NMR (200 MHz, C6D6): d 7.02–7.16 (m, 6H,
Ar-H), 4.82 (s, 1H, g -CH), 3.45 (sept, 2H, CH(CH3)2), 3.37 (sept,
2H, CH(CH3)2), 3.00 (s, 6H, N(CH3)2), 1.65 (s, 6H, CH3), 1.27–
1.35 (m, 18H, CH(CH3)2), 1.17 (d, 6H, CH(CH3)2) ppm. For
comparison see ref. 5.
Synthesis of [{HC(CMeNAr)2}SnCCCO2Et] (Ar
=
2,6-
iPr2C6H3) (5). A solution of HCCCO2Et (0.100 g, 1.00 mmol
in 5 mL toluene) was added drop by drop by cannula to a solution
of 1 (0.490 g, 1.00 mmol in toluene 15 mL) at room temperature.
After 0.5 h under constant stirring at ambient temperature the red
solution turned deep-red. All volatiles were removed in vacuum,
and the remaining residue was extracted with n-hexane (15 mL)
and concentrated to about 5 mL and stored in a freezer at
-30 ◦C. Yellow crystals of 5 suitable for X-ray diffraction a◦nalysis
Synthesis of [{HC(CMeNAr)2}SnOCPh(CF3)nMe2] (Ar =
2,6-iPr2C6H3) (2). A solution of 2-benzoylpyridine (0.180 g,
1.00 mmol in 5 mL toluene) was added by cannula to a solution
of 1 (0.54 g, 1.00 mmol in toluene 20 mL) at room temperature.
After 12 h all volatiles were removed in vacuum, and the remaining
residue was extracted with n-hexane (25 mL) and concentrated to
about 15 mL and stored in a freezer at -30 ◦C. Yellow crystals of 2
suitable for X-ray diffraction analysis are formed after four days.
1
are formed after two days. Yield: 0.495 g (78%); mp 164 C. H
NMR (200 MHz, C6D6): d 7.05–7.19 (m, 6H, Ar–H), 4.99 (s, 1H,
g -CH), 3.84–4.01 (m, 4H, CH(CH3)2, CH2CH3), 3.26 (sept, 2H,
CH(CH3)2), 1.60 (s, 6H, CH3), 1.51 (d, 6H, CH(CH3)2), 1.40 (d,
6H, CH(CH3)2), 1.23 (d, 6H, CH(CH3)2), 1.11 (d, 6H, CH(CH3)2),
0.92 (t, 3H, CH2CH3) ppm. 119Sn NMR (186.50 MHz, C6D6): d
-252.97 ppm. EI-MS: m/z (%) 562 (100) [M-Et-iPr]+. Found C,
◦
1
Yield: 0.670 g (88%); mp 176 C. H NMR (200 MHz, C6D6): d
8.24 (d, 2H, o-Ph-H), 7.60 (d, 1H, o-Py-H), 7.33 (t, 2H, m-Ph-H),
7.03-7.16 (m, 6H, Ar-H), 6.83-6.79 (m, 2H, p-Ph-H, p-Py-H), 6.3
(m, 2H, m-Py-H), 4.95 (s, 1H, g -CH), 4.21 (sept, 1H, CH(CH3)2),
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 4647–4650 | 4649
©

View Article Online
63.88; H, 6.98; N, 4.48. Calcd. for C34H46N2O2Sn (634.26): C,
64.47; H, 7.32; N, 4.42.
(d) M. F. Lappert and R. S. Rowe, Coord. Chem. Rev., 1990, 100, 267–
292.
2 (a) A. Jana, D. Ghoshal, H. W. Roesky, I. Objartel, G. Schwab and
D. Stalke, J. Am. Chem. Soc., 2009, 131, 1288–1293; A. Jana, S. S.
Sen, H. W. Roesky, C. Schulzke, S. Dutta and S. K. Pati, Angew. Chem.,
2009, 121, 4310–4312; (b) A. Jana, S. S. Sen, H. W. Roesky, C. Schulzke,
S. Dutta and S. K. Pati, Angew. Chem., Int. Ed., 2009, 48, 4246–4248;
(c) A. Jana, H. W. Roesky and C. Schulzke, Dalton Trans., 2010, 39,
132–138.
3 (a) A. Jana, H. W. Roesky, C. Schulzke and A. Do¨ring, Angew. Chem.,
2009, 121, 1126–1129; A. Jana, H. W. Roesky, C. Schulzke and A.
Do¨ring, Angew. Chem., Int. Ed., 2009, 48, 1106–1109; (b) A. Jana,
H. W. Roesky and C. Schulzke, Inorg. Chem., 2009, 48, 9543–9548.
4 C. Silvestru, H. J. Breunig and H. Althaus, Chem. Rev., 1999, 99, 3277–
3327.
5 P. Dove, V. C. Gibson, E. D. Marshall, H. S. Rzepa, A. J. P. White and
D. J. Williams, J. Am. Chem. Soc., 2006, 128, 9834–9843.
6 Y. Ding, H. W. Roesky, M. Noltemeyer, H.-G. Schmidt and P. P. Power,
Organometallics, 2001, 20, 1190–1194.
7 L. W. Pineda, V. Jancik, K. Starke, R. B. Oswald and H. W. Roesky,
Angew. Chem., 2006, 118, 2664–2667; L. W. Pineda, V. Jancik, K. Starke,
R. B. Oswald and H. W. Roesky, Angew. Chem., Int. Ed., 2006, 45,
2602–2605.
Crystallographic details of 2 and 5. The data set of 2 was
collected on a Bruker TXS-Mo rotating anode equipped with
INCOATEC Helios mirror optics and the data set of 5 was
collected on a INCOATEC Mo micro source equipped with
17
˚
INCOATEC quazar mirror optics (MoKa l = 0.71073 A).
The crystals were mounted in a shock-cooled oil drop at the tip
of a fibre.18 The data were integrated with SAINT V7.46A (2),
and SAINT V7.60A (5),19 and an empirical absorption correction
SADABS-2008/2 (2, 5) was applied.20 The structures were solved
by direct methods (SHELXS)21 and refined on F2 using the full-
matrix least-squares method of SHELXL.22 All non-hydrogen
atoms were refined with anisotropic displacement parameters. All
hydrogen atoms were assigned ideal positions and refined using a
riding model with Uiso constrained to 1.2 (1.5) times the Ueq value
of the parent carbon atom. Crystallographic data are presented in
Table 1.
8 A. Jana, H. W. Roesky, C. Schulzke, A. Do¨ring, T. Beck, A. Pal and R.
Herbst-Irmer, Inorg. Chem., 2009, 48, 193–197.
9 (a) W. Wang, S. Inoue, S. Yao and M. Driess, Chem. Commun., 2009,
2661–2663; (b) S. Inoue and M. Driess,, Organometallics, 2009, 28,
5032–5035.
Conclusion
In conclusion the results show that the tin(II)-alkoxides have
been prepared by the reaction of 1 with ketones resulting in
compounds containing the Sn(II)–O–CNMe2 core. Furthermore,
tin(II)-dimethylamide reacts with terminal alkynes generating
the alkynyl substituted tin(II) compounds under elimination of
10 A. Jana, I. Objartel, H. W. Roesky and D. Stalke, Inorg. Chem., 2009,
48, 798–800.
11 (a) J. Zhang, R. Cai, L. Weng and X. Zhou, Organometallics, 2004, 23,
3303–3308; (b) C. Pi, Z. Zhang, Z. Pang, J. Zhang, J. Luo, Z. Chen, L.
Weng and X. Zhou, Organometallics, 2007, 26, 1934–1946.
12 B. Nekoueishahraki, S. P. Sarish, H. W. Roesky, D. Stern, C.
Schulzke and D. Stalke, Angew. Chem., 2009, 121, 4587–4590; B.
Nekoueishahraki, S. P. Sarish, H. W. Roesky, D. Stern, C. Schulzke
and D. Stalke, Angew. Chem., Int. Ed., 2009, 48, 4517–4520.
13 (a) T. A. George and M. F. Lappert, J. Organomet. Chem., 1968, 14,
327–337; (b) R. H. Cragg and M. F. Lappert, J. Chem. Soc. A, 1966,
82–85.
≡
dimethyl amine rather than the addition of 1 to the C C triple
bond. 2–5 represent a class of compounds with low valent group
14 elements and an electron lone pair at tin(II) that is prone for
complexation reaction with transition metal fragments or Lewis
acids. Moreover, it is interesting to mention that all the compounds
are stable in air and moisture and highly soluble in common
organic solvents.
14 P. Zhao, C. Krug and J. F. Hartwig, J. Am. Chem. Soc., 2005, 127,
12066–12073.
15 E. Katayev, Y. Li and A. L. Odom, Chem. Commun., 2002, 838–839.
16 A. R. Katritzky, Comprehensive Organic Functional Transformations,
Elsevier Pergamon: Amsterdam 1995.
17 T. Schulz, K. Meindl, D. Leusser, D. Stern, J. Graf, C. Michaelsen,
M. Ruf, G. M. Sheldrick and D. Stalke, J. Appl. Crystallogr., 2009, 42,
885–891.
18 (a) T. Kottke and D. Stalke, J. Appl. Crystallogr., 1993, 26, 615–619;
(b) T. Kottke, R. J. Lagow and D. Stalke, J. Appl. Crystallogr., 1996, 29,
465–468; (c) D. Stalke, Chem. Soc. Rev., 1998, 27, 171–178.
19 SAINT v7.46A in Bruker APEX v2.2-0, Bruker AXS Inst. Inc., Madison
(WI, USA), 2005.
Acknowledgements
This work was supported by the Deutsche Forschungsgemein-
schaft. The authors thank the state Niedersachsen und the
Volkswagenstiftung for superb X-ray equipment.
20 G. M. Sheldrick, SADABS 2008/2, Go¨ttingen, 2008.
21 G. M. Sheldrick, SHELXS in SHELXTL v6.10, Bruker AXS Inst. Inc.,
Madison (WI), USA, 2000.
References
1 (a) S. Nagendran and H. W. Roesky, Organometallics, 2008, 27, 457–
492; (b) Y. Mizuhata, T. Sasamori and N. Tokitoh, Chem. Rev., 2009,
109, 3479–3511; (c) W. P. Neumann, Chem. Rev., 1991, 91, 311–334;
22 G. M. Sheldrick, Acta Crystallogr., Sect. A: Found. Crystallogr., 2008,
64, 112–122.
4650 | Dalton Trans., 2010, 39, 4647–4650
This journal is
The Royal Society of Chemistry 2010
©