U. Braun, T. Habereder, H. Nöth
a solution of tmp2AlCl (3.0 mmol, 12.6 mL of a 0.238 solution crystals separated. Also, distillation did not allow 10 to be sepa-
FULL PAPER
in hexane). The turbid mixture was then maintained at reflux for
1 d; 50% of 1 had reacted to a new compounds with δ11B ϭ 35.7
ppm. Additional heating afforded no change in the 11B NMR spec-
trum. The precipitate that had formed was filtered off. The yellow
filtrate was then kept at Ϫ20 °C, providing a small amount of crys-
tals of 6 that showed an 11B NMR signal at δ ϭ 35.5 ppm but no
27Al NMR signal; m.p. 210 °C (dec.). C28H51BLiN3 (447.47): calcd.
C 75.16, H 11.49, N 9.39; found C 72.93, H 10.65, N 8.98. MS
(70 eV): m/z (%) ϭ 299 (100) [Mϩ Ϫ tmpH Ϫ Li], 284 (100) [299
Ϫ Meϩ], 243 (12) [299 Ϫ Buϩ], 126 (100) [tmp Ϫ Meϩ].
rated from the by-products.
[(tert-Butyl)(trichlorogermyl)amino](phenyl)(2,2,6,6-tetramethyl-
piperidino)borane (11): The solvent from a freshly prepared solution
of 1 (1.77 mmol) in hexane (30 mL) was removed and the residue
dissolved in diethyl ether (40 mL). GeCl4 (0.3 mL) was then added
to this solution, and the resultant suspension kept at reflux for 2 h.
Since no complete conversion was noted the mixture was main-
tained at reflux for 5 days, after which only a single 11B NMR
signal was seen. The ether was then removed and the resultant oily
residue treated with hexane (40 mL). On reducing the filtrate’s vol-
ume to about 50%, crystals of 11 separated at Ϫ20 °C. Yield: 0.63 g
(75%), m.p. 205 °C. C19H32BCl3GeN2 (478.22): calcd. C 47.68, H
6.69, N 5.85, Cl 22.24; found C 47.45, H 6.73, N 5.75, Cl 20.91.
2-tert-Butyl-3,3,5,5,9,9-hexamethyl-1-phenyl-2-aza-4-azonia-1-bora-
3-aluminataspiro[3.5]nonane (7): A 1 solution of Me2AlCl in hex-
ane (3 mL) was added to a suspension of 1 with LiCl (3.0 mmol 1
in 30 mL of hexane/diethyl ether) at room temperature. After stir-
ring for 1 h the insoluble material was filtered off and the so-ob-
tained colorless solution reduced to 15 mL. At Ϫ20 °C, colorless,
moisture and air-sensitive crystals separated. Yield: 0.92 g of 7
(86%), m.p. 160 °C. C21H38AlBN2 (356.32): calcd. C 70.72, H
10.66, N 7.88; found C 63.81, H 9.17, N 6.70. 1H NMR (C6D6):
δ ϭ Ϫ0.06 (s, 6 H, AlMe2) ppm. 13C NMR ((C6D6): δ ϭ 0.24 (br.,
AlMe2) ppm. 27Al NMR (C6D6): δ ϭ 164, (h1/2 ϭ 1800 Hz) ppm.
MS (70 eV): m/z (%) ϭ 356 (8.5) [Mϩ], 341 (100) [Mϩ Ϫ Me], 300
(21.5) [Mϩ Ϫ Bu], 284 (100) [Mϩ Ϫ Me Ϫ Bu], 269 (64) [284 Ϫ
Meϩ], 256 (32) [Me2NBuϩ], 228 (36.5) [tmpBPhϩ], 216 (100) [Mϩ
Ϫ tmp], 183 (100) [tmpAlMeϩ], 159 (100) [PhBNBuϩ].
[(tert-Butyl)(trimethylstannyl)amino](phenyl)(2,2,6,6-tetramethyl-
piperidino)borane (12): Prepared in analogy to 11 from 1 in hexane
(3.0 mmol, 20 mL) and Me3SnCl (0.76 g, 2.8 mmol) in hexane
(15 mL). The suspension was then stirred for 2 days. Although only
the 11B NMR signal of 12 (δ ϭ39.8 ppm) was noted, the first crys-
tals that separated from the filtrate at Ϫ20 °C proved to be
Me3SnCl. These were removed and the filtrate kept at Ϫ78 °C to
afford crystals of 12. Yield: 0.97 g (70%), m.p. 98 °C. C22H41BN2Sn
(464.24): calcd. C 57.01, H 8.85, N 6.05; found C 54.80, H 8.68, N
1
5.68. H NMR (C6D6): δ ϭ 0.08 [t, 2J(119Sn1H) ϭ 56.3 Hz, 9 H]
ppm. 13C NMR (C6D6): δ ϭ 1.4 [1J(119Sn13C) ϭ 395.1 Hz] ppm.
119Sn NMR (C6D6): δ ϭ 17.9 ppm. MS (70 eV): m/z (%) ϭ 464
(22) [Mϩ], 449 (100) [Mϩ Ϫ Me], 324 (100) [Mϩ Ϫ tmp], 165
(100) [SnMe3ϩ].
2-tert-Butyl-3,3,5,5,9,9-hexamethyl-1-phenyl-2-aza-4-azonia-1-bora-
3-gallataspiro[3.5]nonane (8): Prepared in analogy to 7 by using
Me2GaCl (0.45 g, 3.0 mmol) dissolved in hexane (30 mL) to furnish
very moisture- and air-sensitive crystals of 8. Yield: 1.05 g (88%).
C21H38BGaN2 (399.06): calcd. C 63.1, H 9.52, N 7.02; found C
58.18, H 8.43, N 6.29. 1H NMR (C6D6): δ ϭ 0.32 (s, GaMe
ppm.13C NMR (C6D6): δ ϭ 1.13 (GaMe2) ppm. MS (70 eV): m/z
(%) ϭ 399 (0.5) [Mϩ], 384 (43) [Mϩ Ϫ Me], 297 (9.5) [GaMe2ϩ?],
224 (42) [tmpGaMeϩ], 126 (11.5) [tmp Ϫ Meϩ].
[(tert-Butyl)(chlorodimethylstannyl)amino](phenyl)(2,2,6,6-tetra-
methylpiperidino)borane (13): A solution of Me2SnCl2 (0.44 g,
2.0 mmol) dissolved in boiling hexane (50 mL) was added to freshly
prepared 1 (2.0 mmol) in hexane (30 mL) kept at Ϫ78 °C. The re-
sulting suspension showed, at ambient temperature, only a single
11B NMR signal at δ ϭ 39.4 ppm. The filtrate was then reduced to
20 mL, and on cooling to Ϫ20 °C crystals of 13 separated. Yield:
0.71 g (73%), m.p. 145 °C (dec.). C21H38BClN2Sn (483.48): calcd.
2-tert-Butyl-3,3,5,5,9,9-hexamethyl-1-phenyl-2-aza-4-azonia-1-bora-
3-indataspiro[3.5]nonane (9): Prepared in analogy to 7 by using
Me2InCl (0.54 g, 3.0 mmol) dissolved in hexane (20 mL), with
workup after stirring for 5 h. The filtrate was then reduced to ca.
20 mL. Crystals of 9 separated from the solution at Ϫ78 °C. Yield:
0.90 g (68%), m.p. Ͼ 200 °C. C21H38BInN2 (444.16): calcd. C 56.74,
1
C 52.12, H 7.86, N 5.79; found C 45.67, H 7.51, N 5.74. H NMR
2
(C6D6): δ ϭ 0.02 [d, J(119Sn1H) ϭ 52 Hz, 6 H, SnMe2] ppm. 13C
NMR (C6D6): δ ϭ Ϫ2.6 [1J(119Sn13C) ϭ 390 Hz] ppm. 119Sn NMR
(C6D6): δ ϭ 93.1 ppm.
Reaction of Me2SnCl2 with 1 in a 1:2: Ratio: In analogy to 13,
Me2SnCl2 (2.0 mmol) in hexane (50 mL) was reacted with 1
[4.0 mmol in hexane (40 mL)] at Ϫ78 °C. The 11B NMR spectrum
of the suspension showed, at ambient temperature, a signal at δ ϭ
39.2 ppm in addition to that of the starting material. After 3 days,
additional signals appeared at δ ϭ 48.3 and δ ϭ 5.4 ppm. A 119Sn
NMR spectrum revealed a signal at δ ϭ 98.3 ppm, corresponding
to tmpMe2SnCl, while the 11B NMR signal at δ ϭ 39.2 ppm is
typical for (tBuNBPh)2.[23]
1
H 8.56, N 6.30; found C 51.04, H 7.96, N 5.78. H NMR (C6D6):
δ ϭ 0.06 (s, InMe2) ppm. 13C NMR (CDCl3): δ ϭ 1.0 (InMe2) ppm.
Insufficient protection against air for 7Ϫ9 is responsible for the
large deviation between calculated and found values in the elemen-
tal analysis.
[(tert-Butyl)(trimethylsilyl)amino](phenyl)(2,2,6,6-tetramethyl-
piperidino)borane (10): Li(tmp) (0.87 g, 5.9 mmol) was suspended
in hexane (30 mL). After cooling the suspension to Ϫ78 °C, a solu-
tion of PhBCl2 (0.78 mL, 5.9 mmol) in hexane (5 mL) was added
with stirring. At room temperature only a single signal at δ11B ϭ
{(tert-Butyl)[chlorostannyl(II)]amino}(phenyl)(2,2,6,6-tetramethyl-
piperidino)borane (15): SnCl2 (0.38 g, 2.0 mmol) was dissolved in
41.8 ppm was present, showing the complete conversion of PhBCl2. THF (30 mL) and treated at 0 °C with a freshly prepared solution
The solid was filtered off and the filtrate treated with a freshly
prepared solution of LiNtBu(SiMe3) (5.9 mmol) in hexane
(20 mL). The mixture was then kept under reflux for 5 d. Three
of 1 (4.0 mmol) in hexane (40 mL). A suspension formed, and the
11B NMR spectrum shows a 50% conversion of 1. On further stir-
ring, no change was observed. After filtration and removal of sol-
11B NMR signals, at δ ϭ 34.2 (60%), 23.4 (15%) and at 28.0 (25%) vent in vacuo a yellow oil remained that was dissolved in hexane
ppm, were detected, the first of which corresponds to 10. In ad-
(20 mL). At Ϫ20 °C compound 15 separated as a slightly yellow
solid that is soluble in benzene, tetrahydrofuran or chloroform. No
dition, three 27Si NMR signals were found at δ ϭ 9.1 (main signal),
17.6 and δ ϭ 8.0 ppm. After removal of the hexane in vacuo the single crystals separated from these solutions. C19H32BClN2Sn
residue was treated with hexane (10 mL), the solid was removed by
filtration and the so-obtained yellow solution kept at Ϫ20 °C. No
(454.14): calcd. C 50.33, H 7.11, N 6.18; found C 48.75, H 7.05, N
5.51. MS (70 eV): m/z (%) ϭ 454 (9) [Mϩ], 439 (25) [Mϩ Ϫ Me],
3640
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2004, 3629Ϫ3643