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86.47; H, 7.02; N 6.51. Found: C, 86.45; H, 7.03; N, 6.50. 1H 170.0 (NCMe); EI-HRMS: m/z calcd for [M − CH3]+: 319.1755;
NMR (400 MHz, CDCl3): 1.92 (s, 6H, CH3), 4.60 (s, 1H, γ-CH), found: 319.1750.
NacnacCH CH PhAlMe2 (2e). Complex 2e was synthesized
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5.75 (s, 2H, CHPh2), 7.15–7.26 (m, 20H, Ar-H), 12.12 (s, 1H,
N-H); 13C NMR (100 MHz, CDCl3): 19.9 (CMe), 64.6 (CHPh2), using the same procedure as that of 2a, except that 1e was
96.3 (CH), 126.6 (Ar-C), 127.6(Ar-C), 128.4 (Ar-C), 144.4 (Ar-C), used. Yield: 0.12 g (73%). Anal. calcd for C23H31AlN2: C, 76.21;
160.2 (NCMe); ESI-HRMS: m/z calcd for [M + H]+: 431.2487; H, 8.62; N, 7.73. Found: C, 76.24; H, 8.66; N, 7.72. 1H NMR
found: 431.2496.
(400 MHz, CDCl3): −0.74 (s, 6H, AlCH3), 1.98 (s, 6H, CH3), 2.81
NacnacCH AlMe2 (2a). A solution of AlMe3 (0.8 mL of 1.0 M (m, 4H, CH2CH2Ph), 3.46 (m, 4H, CH2CH2Ph), 4.57 (s, 1H,
solution in n-hexane, 0.80 mmol) was added dropwise to a γ-CH), 7.21–7.33 (m, 10H, Ar-H); 13C NMR (100 MHz, CDCl3):
solution of 1a (0.16 g, 0.73 mmol) in n-hexane (10 mL) at room −9.4 (AlCH3), 20.8 (CMe), 37.9 (CH2CH2Ph), 49.5
temperature with rapid stirring. The resulting solution was (NCH2CH2Ph), 96.5 (CH), 126.4 (Ar-C), 128.6 (Ar-C), 128.7
stirred overnight and filtered. The filtrate was concentrated to (Ar-C), 139.4 (Ar-C), 167.7 (NCMe); EI-HRMS: m/z calcd for
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approximately 2 mL and kept at −30 °C for 24 h to give color- [M − CH3]+: 347.2068; found: 347.2064.
less crystals. Single crystals of complex 2a were obtained by
NacnacCHPh AlMe2 (2f). A solution of AlMe3 (0.56 mL of
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slowly cooling a saturated n-hexane solution to −7 °C. Yield: 1.0 M solution in n-hexane, 0.56 mmol) was added dropwise to
0.09 g (70%). Anal. calcd for C9H19AlN2: C, 59.31; H, 10.51; N, a solution of β-diketimine 1f (0.22 g, 0.51 mmol) in toluene
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15.37. Found: C, 59.33; H, 10.50; N, 15.38. H NMR (400 MHz, (5 mL) at room temperature with rapid stirring. The reaction
CDCl3): −0.90 (s, 6H, AlCH3), 1.93 (s, 6H, CCH3), 2.87 (s, 6H, mixture was stirred overnight and then filtered. The filtrate
NCH3), 4.57(s, 1H, γ-CH); 13C NMR (100 MHz, CDCl3): −11.3 was dried under vacuum, and the residue was recrystallized
(AlCH3), 21.2 (CMe), 33.8 (NMe), 95.1 (CH), 168.7 (NCMe); with n-hexane/toluene. 2f deposited after 24 h at −30 °C as
EI-HRMS: m/z calcd for [M − CH3]+: 167.1129; found: 167.1136. pale yellow crystals. Yield: 0.15 g (61%). Anal. calcd for
NacnaciPrAlMe2 (2b). Complex 2b was synthesized using the C33H35AlN2: C, 81.45; H, 7.25; N, 5.76. Found: C, 81.43; H,
same procedure as that of 2a, except that 1b was used. Yield: 7.24; N, 5.72. 1H NMR (400 MHz, CDCl3): −1.48 (s, 6H, AlCH3),
0.38 g (72%). Anal. calcd for C13H27AlN2: C, 65.51; H, 11.42; N, 1.94 (s, 6H, CH3), 4.81 (s, 1H, γ-CH), 6.17 (s, 2H, CHPh2),
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11.75. Found: C, 65.50; H, 11.41; N, 11.72. H NMR (400 MHz, 7.21–7.32 (m, 20H, Ar-H); 13C NMR (100 MHz, CDCl3): −8.3
CDCl3): −0.75 (s, 6H, AlCH3), 1.26 (d, J = 6.8 Hz, 12H, CH (AlCH3), 24.5 (CMe), 65.6 (CHPh2), 99.7 (CH), 127.1 (Ar-C),
(CH3)2), 1.99 (s, 6H, CH3), 3.86 (sept, J = 6.8 Hz, 2H, CH(CH3)2), 128.2 (Ar-C), 129.2 (Ar-C), 141.2 (Ar-C), 169.1 (NCMe);
4.45 (s, 1H, γ-CH); 13C NMR (100 MHz, CDCl3): −4.5 (AlCH3), EI-HRMS: m/z calcd for [M − CH3]+: 471.2381; found: 471.2401.
22.5 (CMe), 23.4 (CH(CH3)2), 49.9 (CH(CH3)2), 96.5 (CH), 165.7
(NCMe); EI-HRMS: m/z calcd for [M − CH3]+: 223.1755; found: solution in n-hexane, 2.64 mmol) was added dropwise to a
223.1749.
NacnactBuAlEt2 (2g). A solution of AlEt3 (1.20 mL of 2.2 M
solution of β-diketimine 1c (0.49 g, 2.30 mmol) in toluene
NacnactBuAlMe2 (2c). Complex 2c was synthesized using the (15 mL) at room temperature with rapid stirring. The reaction
same procedure as that of 2a, except that 1c was used. Single mixture was stirred overnight and then filtered. The filtrate
crystals of aluminum complex 2c were obtained by slowly was dried under vacuum, and the residue was recrystallized
cooling a saturated n-hexane solution to 0 °C. Yield: 0.35 g with n-hexane. 2g deposited after 24 h at −30 °C as yellow crys-
(76%). Anal. calcd for C15H31AlN2: C, 67.63; H, 11.73; N, 10.52. tals. Yield: 0.35 g (52%). Anal. calcd for C17H35AlN2: C, 69.34;
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Found: C, 67.64; H, 11.73; N, 10.55. 1H NMR (400 MHz, H, 11.98; N, 9.51. Found: C, 69.36; H, 11.94; N, 9.52. H NMR
CDCl3): −0.64 (s, 6H, AlCH3), 1.47 (s, 18H, C(CH3)3), 2.14 (s, (400 MHz, CDCl3): −0.14 (q, J = 8 Hz, 4H, AlCH2CH3), 0.92 (t,
6H, CH3), 4.38 (s, 1H, γ-CH); 13C NMR (100 MHz, CDCl3): 0.9 J = 8 Hz, 6H, AlCH2CH3), 1.41 (s, 18H, C(CH3)3), 2.07 (s, 6H,
(AlCH3), 26.1 (CMe), 32.2 (C(CH3)3), 56.3 (C(CH3)3), 99.4 (CH), CH3), 4.31 (s, 1H, γ-CH); 13C NMR (100 MHz, CDCl3): 9.0
166.8 (NCMe); EI-HRMS: m/z calcd for [M − CH3]+: 251.2068; (AlCH2CH3), 9.1 (AlCH2CH3), 26.05 (CMe), 32.20(C(CH3)3),
found: 251.2055.
56.22 (C(CH3)3), 99.73 (CH), 166.98 (NCMe); EI-HRMS: m/z
NacnacCH PhAlMe2 (2d). A solution of AlMe3 (2.45 mL of 1 M calcd for [M − CH3]+: 265.2224; found: 265.2231.
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solution in n-hexane, 2.45 mmol) was added dropwise to a
NacnactBuAliBu2 (2h). A solution of AliBu3 (2.90 mL of 1.1 M
solution of β-diketimine 1d (0.60 g, 2.14 mmol) in toluene solution in toluene, 3.19 mmol) was added dropwise to a solu-
(20 mL) at room temperature with rapid stirring. The reaction tion of β-diketimine 1c (0.61 g, 2.90 mmol) in n-hexane
mixture was stirred for additional 0.5 h and then filtered. The (12 mL) at room temperature with rapid stirring. The reaction
filtrate was dried under vacuum, and the residue was dissolved mixture was stirred overnight and filtered. After the filtrate
with 10 mL n-hexane. The resulting solution was concentrated was dried under vacuum, the residue was recrystallized with
and kept at −30 °C for 24 h to give pale yellow crystals. Yield: n-hexane. 2h deposited after 24 h at −30 °C as colorless
0.61 g (85%). Anal. calcd for C21H27AlN2: C, 75.42; H, 8.14; N, crystals. Single crystals of complex 2h were obtained by slowly
8.38. Found: C, 75.45; H, 8.14; N, 8.37. 1H NMR (400 MHz, cooling a saturated n-hexane solution to −7 °C. Yield: 0.75 g
CDCl3): −0.98 (s, 6H, AlCH3), 1.90 (s, 6H, CH3), 4.55 (s, 4H, (74%). Anal. calcd for C21H43AlN2: C, 71.95; H, 12.36; N, 7.99.
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CH2Ph), 4.71 (s, 1H, γ-CH), 7.21–7.34 (m, 10H, Ar-H); 13C NMR Found: C, 71.96; H, 12.34; N, 8.02. H NMR (400 MHz, CDCl3):
(100 MHz, CDCl3): −9.9 (AlCH3), 22.0 (CMe), 50.7 (CH2Ph), 0.01(d, J = 8 Hz, 4H, AlCH2), 0.88 (d, J = 8 Hz, 12H, AlCH2CH
97.1(γ-CH), 126.7 (Ar-C), 126.8 (Ar-C), 128.6 (Ar-C), 139.8 (Ar-C), (CH3)2), 1.50 (s, 18H, C(CH3)3), 1.81 (sept, J = 8 Hz, 2H,
This journal is © The Royal Society of Chemistry 2013
Dalton Trans., 2013, 42, 11295–11303 | 11301