Organometallics
ARTICLE
(toluene-d8, 300 MHz, 293 K): δ 0.93 (s, 12H, CH3), 1.00 (t, 3H, 3JHH
6 Hz, CH3), 1.32 (m, 4H, CH2), 1.38 (m, 2H, CH2), 2.33 (q, 2H, 3JHH
6 Hz, CH2).
=
=
3JFF = 23 Hz, m-C6F5). 11B{1H} NMR (toluene-d8, 96 MHz, 293 K): δ
ꢀ18.5 (s). 13C{1H} NMR (toluene-d8, 75 MHz, 293 K): δ 148.2 (dm,
1JCꢀF = 245 Hz, o-C6F5), 138.7 (dm, 1JCꢀF = 242 Hz, p-C6F5), 137.3
(dm, 1JCꢀF = 240 Hz, m-C6F5), 65.6 (o-C5H6N), 37.5 (m-C5H6N), 29.1
(CH3), 18.8 (N-CH3), 15.2 (p-C5H6N). Anal. Calcd for C28H23BF15N:
C, 50.25; H, 3.46; N, 2.09. Found: C, 50.52; H, 3.32; N, 1.90.
X-ray crystal structure analysis of 3: formula C28H23BF15N,
Mr = 669.28, triclinic, P1, a = 10.7424(1) Å, b = 11.2219(1) Å, c =
13.6153(1) Å, R = 81.196(1)°, β = 72.844(1)°, γ = 63.415(1)°, V =
1402.06(3) Å3, Z = 2, Dc = 1.585 g cmꢀ3, μ = 0.162 mmꢀ1, λ = 0.71073 Å,
Generation of DMP-B(C6F5)3, 1a. B(C6F5)3 (0.013 g, 0.025 mmol)
and 2,6-dimethylpiperidine (0.0028 g, 0.025 mmol) were dissolved in
C6D6 (0.5 mL), giving a colorless solution. The solution was character-
ized by NMR spectroscopy. 1H NMR (C6D6, 300 MHz, 293 K): δ 0.54
3
(m, 2H, ꢀCH2), 0.71 (m, 2H, ꢀCH2) 0.87 (d, 6H, JHH = 6 Hz,
ꢀCH3), 3.42 (m, 2H, ꢀCH), 5.35 (br, 1H, NH). 11B{1H} NMR (C6D6,
96 MHz, 293 K): δ ꢀ4.3 (s). 19F NMR (C6D6, 282 MHz, 293 K): δ
ꢀ128.2 (br, 2F, o-C6F5), ꢀ128.5 (d, 2F, 3JFF = 23 Hz, o-C6F5), ꢀ138.6
(br, 2F, o-C6F5), ꢀ155.2 (t, 1F, 3JFF = 21 Hz, p-C6F5), ꢀ157.6 (t, 2F,
3JFF = 21 Hz, p-C6F5), ꢀ162.4 (br, 2F, m-C6F5), ꢀ164.4 to ꢀ164.6 (m,
4F, m-C5F5). 13C{1H} NMR (C6D6, 75 MHz, 293 K): δ 149.7 (dm,
1JCꢀF = 240 Hz, o-C6F5), 139.4 (dm, 1JCꢀF = 245 Hz, p-C6F5), 136.3
(dm, 1JCꢀF = 243 Hz, m-C6F5), 51.7 (o-C5H9N), 26.5 (m-C5H9N), 22.8
(CH3), 10.8 (p-C5H9N). Anal. Calcd for C25H15BF15N: C, 48.03; H,
2.42; N, 2.24. Found: C, 48.20; H, 2.47; N, 2.18.
T = 183(2) K, 30 255 reflections collected, 8556 independent (Rint
=
0.0248) and 5955 observed reflections, 419 refined parameters, R[F2 >
2σ(F2)] = 0.0396, wR2(F2) = 0.1098. CCDC 790974.
Preparation of [2,2,6,6-(CH3)4-C5H6NH(CH2CH3)][HB-
(C6F5)3], 4a, and [2,2,6,6-(CH3)4-C5H6NdCHCH2-B(C6F5)3],
4b. B(C6F5)3 (0.1024 g, 0.2 mmol) and 1-ethyl-2,2,6,6-pentamethylpi-
peridine (0. 034 g, 0.2 mmol) were added to a 50 mL Schlenk and
dissolved in toluene (5 mL), giving a yellow solution. After stirring for
10 min at rt, the reaction was then concentrated to half volume, and
hexane was added to promote precipitation. The product was washed
with hexane after filtration and dried in vacuo. The white product
contains a mixture of 4a and 4b in an approximate 3:7 ratio. Yield:
82%. 4b: 1H NMR (C6D6, 300 MHz, 293 K): δ 0.47 (s, 6H, ꢀCH3),
0.72 (s, 6H, ꢀCH3), 0.89 (m, 4H, ꢀCH2), 1.25 (m, 2H, ꢀCH2), 3.17
(br, 2H, dCHꢀCH2), 8.07 (br, 1H, dCH-CH2). 11B{1H} NMR
(C6D6, 96 MHz, 293 K): δ ꢀ13.9 (s). 19F NMR (C6D6, 282 MHz,
293 K): δ ꢀ133.5 (d, 6F, 3JFF = 23 Hz, o-C6F5), ꢀ160.8 (t, 3F, 3JFF = 21
Hz, p-C6F5), ꢀ165.7 (t, 6F, 3JFF = 21 Hz, m-C6F5).
X-ray crystal structure analysis of 1a: formula C25H15BF15N,
Mr = 625.19, orthorhombic, Pca21, a = 17.8991(4) Å, b = 9.0917(2) Å,
c = 14.4468(3) Å, V = 2350.97(9) Å3, Z = 4, Dc = 1.766 g cmꢀ3, μ =
0.186 mmꢀ1, λ = 0.71073 Å, T = 183(2) K, 23 274 reflections collected,
3713 independent (Rint = 0.0710) and 2972 observed reflections, 385
refined parameters, R[F2 > 2σ(F2)] = 0.0431, wR2(F2)= 0.1172. CCDC
698951.
Preparation of [DMPH][HB(C6F5)3], 1b. Solid B(C6F5)3 (0.256 g,
0.5 mmol) and 2,6-dimethylpiperidine (0.0566 g, 0.5 mmol, 0.067 mL)
were added to a 50 mL Schlenk tube and dissolved in toluene (10 mL),
giving a colorless solution. The Schlenk tube was filled with H2 (1 bar),
and the solution was allowed to stir at 110 °C for 20 h. There was no
precipitation formed during this period of time. Then the solvent was
removed under reduced pressure, and a white solid was obtained, which
was washed with pentane. The product was collected as a white solid.
Yield: 71%. 1H NMR (C6D6, 300 MHz, 293 K): δ 0.35 (m, 4H, ꢀCH2),
X-ray crystal structure analysis of 4b: formula C29H21BF15N,
Mr = 679.28, monoclinic, C2/c, a = 23.0895(3) Å, b = 11.0393(2) Å, c =
21.5309(3) Å, β = 90.593(1)°, V = 5487.76(14) Å3, Z = 8, Dc =
1.644 g cmꢀ3, μ = 0.167 mmꢀ1, λ = 0.71073 Å, T = 183(2) K, 26 356
reflections collected, 6799 independent (Rint = 0.0216) and 4967
observed reflections, 435 refined parameters, R[F2 > 2σ(F2)] =
0.0460, wR2(F2) = 0.1314. CCDC 790976.
3
0.52 (d, 6H, JHH = 6 Hz, ꢀCH3), 0.72 (m, 2H, ꢀCH2), 2.01 (br,
1
2H, ꢀCH), 3.44 (q, 1H, JHB = 88 Hz, ꢀBH), 4.52 (br, 2H, ꢀNH).
Preparation of [2,2,6,6-(CH3)4-C5H6NH(CH2CH3)][HB-
(C6F5)3], 4a. Solid B(C6F5)3 (0.1024 g, 0.2 mmol) and 1-ethyl-
2,2,6,6-pentamethylpiperidine (0.034 g, 0.2 mmol) were added to a
50 mL Schlenk and dissolved in toluene (5 mL), giving a colorless
solution. The solution was filled with H2 (1 bar), and the solution was
allowed to stir at 110 °C for 24 h. There was no precipitate formed
during this process. The reaction was then concentrated to half of its
original volume, and pentane was added to induce precipitation. The
product was washed with pentane after filtration and dried in vacuo. The
11B{1H} NMR (C6D6, 96 MHz, 293 K): δ ꢀ23.9 (s). 19F NMR (C6D6,
282 MHz, 293 K): δ ꢀ135.0 (d, 6F, 3JFF = 23 Hz, o-C6F5), ꢀ162.5 (t,
3
3
3F, JFF = 23 Hz, p-C6F5), ꢀ166.6 (t, 6F, JFF = 21 Hz, m-C6F5).
13C{1H} NMR (C6D6, 75 MHz, 293 K): δ 148.8 (dm, 1JCꢀF = 248 Hz,
o-C6F5), 139.1 (dm, 1JCꢀF = 250 Hz, p-C6F5), 137.3 (dm, 1JCꢀF = 247
Hz, m-C6F5), 56.7 (o-C5H9N), 29.6 (m-C5H9N), 22.7 (CH3), 18.8 (p-
C5H9N). Anal. Calcd for C25H17BF15N: C, 47.87; H, 2.73; N, 2.23.
Found: C, 47.92; H, 2.54; N, 2.10.
1
X-ray crystal structure analysis of 1b: formula C63H48-
B2F30N2, Mr = 1424.65, monoclinic, P21/n, a = 12.3238(2) Å, b =
16.6160(2) Å, c = 15.7963(2) Å, β = 107.804(2)°, V = 3079.73(8) Å3,
Z = 2, Dc = 1.536 g cmꢀ3, μ = 0.153 mmꢀ1, λ = 0.71073 Å, T = 183(2) K,
41 687 reflections collected, 6301 independent (Rint = 0.0281) and 4570
observed reflections, 443 refined parameters, R[F2 > 2σ(F2)] = 0.0632,
wR2(F2) = 0.1882. CCDC 790973.
product was collected as a white solid. Yield: 81%. H NMR (C6D6,
300 MHz, 293 K): δ 0.28 (s, ꢀCH3), 0.39 (s, ꢀCH3), 0.46 (s, ꢀCH3),
0.52 (s, ꢀCH3), 0.55 (t, 3JHH = 6 Hz, ꢀCH2-CH3), 0.64 (t, 3JHH = 6 Hz,
ꢀCH2-CH3), 0.86 (m, ꢀCH2), 1.91 (m, ꢀCH2-CH3), 2.03 (m, ꢀ
CH2-CH3), 2.37 (br, BH), 4.24 (br, NH). 19F NMR (C6D6, 282 MHz,
293 K): δ ꢀ134.1 (d, 3JFF = 21 Hz, o-C6F5), ꢀ134.4 (d, 3JFF = 21 Hz, o-
3
3
C6F5), ꢀ164.5 (t, JFF = 23 Hz, p-C6F5), ꢀ165.5 (t, JFF = 23 Hz, p-
C6F5), ꢀ167.7 (t, 3JFF = 21 Hz, m-C6F5), ꢀ168.4 (t, 3JFF = 21 Hz, m-
C6F5). 11B{1H} NMR (C6D6, 96 MHz, 293 K): δ ꢀ25.1 (s). 1H NMR
(CDCl3, 300 MHz, 293 K): δ 1.46 (s, 6H, ꢀCH3), 1.53 (s, 6H, ꢀCH3),
Preparation of [PMPH][HB(C6F5)3], 3. B(C6F5)3 (0.1024 g,
0.2 mmol) and 1,2,2,6,6-pentamethylpiperidine (0.031 g, 0.2 mmol)
were added to a 50 mL Schlenk tube and dissolved in toluene (5 mL),
giving a yellow solution. The Schlenk tube was filled with H2 (1 bar), and
the solution was allowed to stir at rt for 2 h. There was no precipitate
formed during this process. The reaction was then concentrated to half
of its volume, and hexane was added to induce precipitation. The
product was washed with hexane after filtration and dried in vacuo.
3
1.56 (t, 3H, JHH = 6 Hz, ꢀCH2-CH3), 1.86 (qd, 2H, JHH = 6, 3 Hz,
ꢀCH2-CH3), 3.51 (br, BH), 4.00 (br, NH). 19F NMR (CDCl3, 282 MHz,
3
3
293 K): δ ꢀ134.8 (d, JFF = 21 Hz, o-C6F5), ꢀ164.5 (t, JFF = 21 Hz,
p-C6F5), ꢀ167.8 (t, JFF = 20 Hz, m-C6F5). 11B{1H} NMR (C6D6,
3
96 MHz, 293 K): δ ꢀ25.2 (s).
1
Yield: 82%. H NMR (toluene-d8, 300 MHz, 293 K): δ 0.28 (s, 6H,
X-ray crystal structure analysis of 4a: formula C29H25BF15N,
Mr = 683.31, monoclinic, P21, a = 10.2209(6) Å, b = 15.4745(6) Å,
c = 10.1157(6) Å, β = 114.872(7)°, V = 1451.54(16) Å3, Z = 2, Dc =
1.563 g cmꢀ3, μ = 0.158 mmꢀ1, λ = 0.71073 Å, T = 183(2) K, 23 737
reflections collected, 3742 independent (Rint = 0.0365) and 3418 observed
CH3), 0.57 (s, 6H, CH3), 0.84 (m, 4H, CH2), 1.08 (m, 2H, CH2), 1.80
(d, 3H, 3JHH = 6 Hz, N-CH3), 3.78 (q, 1H, 1JHB = 82 Hz, BH), 4.49 (br,
2H, NH). 19F NMR (toluene-d8, 282 MHz, 293 K): δ ꢀ134.3 (d, 6F,
3JFF = 23 Hz, o-C6F5), ꢀ163.6 (t, 3F, 3JFF = 23 Hz, p-C6F5), ꢀ167.3 (t, 6F,
2123
dx.doi.org/10.1021/om100951a |Organometallics 2011, 30, 2117–2124