Compound 2x

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Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

3,5-dimethylaniline (2.0 mL, 1.9 g, 16 mmol), 4-iodoanisole (9.39 g, 40.1 mmol), 18-crown-6 (0.85 g, 3.2 mmol), copper powder (4.08 g, 64.2 mmol), and K₂CO₃ (17.73 g, 128.0 mmol) were suspended in a 250 mL round-bottom flask containing o-dichlorobenzene (31 mL) and refluxed for 72 h under a stream of dinitrogen. The resulting heterogeneous solution was then cooled to room temperature prior to addition of 100 mL EtOAc. The solid byproduct was removed by gravity filtration and solvent was removed from the filtrate by vacuum distillation to yield an oil that was purified by column chromatography (SiO₂: pet. ether/CH₂Cl₂, 1:1). The desired fraction (R_f: 0.18) was isolated, solvent removed by rotary evaporation and the crude solid recrystallized in hot MeOH to yield a colorless solid (4.40 g, 13.2 mmol, 82 %). ¹H NMR (300 MHz, CDCl₃): δ = 7.07 (d, 4H, ³J = 9.0 Hz, H_k), 6.84 (d, 4H, ³J = 9.0 Hz, H_j), 6.62 (s, 2H, H_i), 6.58 (s, 1H, H_s), 3.82 (s, 6H, H_l), 2.23 (s, 6H, H_h). {¹H}¹³C NMR (100 MHz, CDCl₃): δ = 155.6, 148.9, 141.6, 138.6, 126.4, 122.9, 119.2, 114.68, 55.6, 21.5. HRMS (ESI) calcd for C₂₂H₂₄NO₂: m/z = 334.1807. Found: m/z = 334.1813 [(MH)⁺]. Anal. Calcd for C₂₂H₂₃NO₂: C, 79.25; H, 6.95; N, 4.20. Found: C, 78.95; H, 7.04; N, 4.08.

In the absence of light NBS (0.107 g, 0.599 mmol) was added to a cooled solution (0^°C) of N,N-bis(4'-methoxyphenyl)-3,5-dimethylaniline (0.200 g, 0.599 mmol) in EtOAc (5 mL). The reaction mixture was brought to room temperature and stirred in the dark for 16 h. The organic layer was washed with 3 × 15 mL of H₂O and subsequently dried over MgSO₄. The filtered solution was taken to dryness by rotary evaporation and the resultant solid recrystallized from MeOH to yield 2.02 g (81 %) of a colorless solid. ¹H NMR (300 MHz, CDCl₃): δ = 7.00 (d, 4H, ³J = 8.5 Hz, H_k), 6.81 (d, 4H, ³J = 8.9 Hz, H_j), 6.65 (s, 2H, H_i), 3.80 (s, 6H, H_l), 2.27 (s, 6H, H_h). {¹H}¹³C NMR (100 MHz, CDCl₃): δ =155.9, 147.4, 141.0, 138.7, 126.5, 120.9, 118.5, 114.8, 55.6, 24.0. HRMS (ESI) calcd for C₂₂H₂₃BrNO₂: 412.0912. Found: m/z = 412.0922 [(MH)⁺]. Anal. Calcd for C₂₂H₂₂BrNO₂: C, 64.09; H, 5.38; N, 3.40. Found: C, 64.20; H, 5.46; N, 3.35.

A Schlenk flask was charged with Pd(dppf)Cl₂•CH₂Cl₂ (0.198 g, 0.243 mmol), KOAc (0.357 g, 0.364 mmol) and bis(pinacolato)diboron (0.678 g, 2.67 mmol) and flushed with dinitrogen. To this solution a second solution of 4-bromo-N,N-bis(4'-methoxyphenyl)-3,5-dimethylaniline (0.500 g, 1.27 mmol) in DMSO (9.6 mL, stored over 4 Å molecular sieves and degassed thoroughly with nitrogen before use) was added, and then stirred at 80 °C for 16 h under a flow of dinitrogen. The reaction mixture was cooled to room temperature and diluted with CH₂Cl₂ (50 mL). The mixture was washed with H₂O (3 × 100 mL), dried over MgSO₄, and filtered. The brown solid left upon removal of solvent from the filtrate was solubilized in CH₂Cl₂ and preabsorbed on silica. The solvent was removed and the sample was purified by column chromatography [SiO₂: pet. ether: CH₂Cl₂, 9:1, R_f : 0.27] to yield 0.180 g (32%) of the product as a colorless solid. The identity of the compound was confirmed by ESI-MS and used without further purification.

N-N-bis(4'-methoxyphenyl)-3,5-dimethyl-4-(4'',4'',5'',5''-tetramethyl-1'',3'',2''-dioxaborolan-2''-yl)aniline (0.383 g, 0.835 mmol) and 6-(3'',5''-bis(trifluoromethyl)phenyl)-4-(5'''-bromothiophen-2'''-yl)-2,2'-bipyridine (0.350 g, 0.759 mmol) were solubilized in a THF/ H₂O solution (9:1; 65 mL) and sparged for 10 min with dinitrogen. K₂CO₃ (0.608 g, 4.40 mmol) and Pd(PPh₃)₄ (0.088 g, 0.076 mmol) were added, and the reaction was refluxed for 14 h under a flow of dinitrogen. The reaction mixture was then cooled, and the THF layer was separated and washed with brine. The organic fractions were collected and dried with MgSO₄, filtered, and the solvent was removed in vacuo. The resulting oil was then solubilized in pet. ether/EtOAc (9:1 v/v) and purified by column chromatography (SiO₂: pet. ether/EtOAc, 9:1, R_f: 0.18) to yield 0.105 g (19%) of a bright yellow powder. ¹H NMR (300 MHz, CDCl₃): δ = 8.74 (ddd, 1H, ³J = 4.9 Hz, ⁴J = 1.8 Hz, ⁵J = 0.8 Hz, H_a), 8.67 (d, 1H, ⁴J = 1.5 Hz, H_e), 8.64 (dt, 1H, ³J = 8.0 Hz, ⁴J = 0.8 Hz, H_d), 8.46 (s, 1H, H_n), 8.36 (d, 1H, ³J = 7.6 Hz, H_r), 7.95 (d, 1H, ⁴J = 1.6 Hz, H_m), 7.89 (dt, 1H, ³J = 7.8 Hz, ⁴J = 1.8 Hz, H_c), 7.73-7.71 (m, 2H, H_f, H_p), 7.65 (t, 1H, ³J = 7.8 Hz, H_q), 7.37 (ddd, 1H, ³J = 7.7 Hz, ³J = 4.8 Hz, ⁴J = 1.1 Hz, H_b), 7.11 (d, 4H, ³J = 9.0 Hz, H_k), 6.90-6.85 (m, 5H, H_g, H_j), 6.67 (s, 2H, H_i), 3.82 (s, 6H, H_l), 2.11 (s, 6H, H_h). {¹H}¹³C NMR (100 MHz, CDCl₃): δ = 156.8, 156.1, 156.0, 155.8, 149.3, 148.8, 144.7, 144.0, 141.2, 140.9, 140.3, 139.0, 137.1, 131.3 (q, ²J_CF = 32.2 Hz), 130.4, 129.3, 128.5, 127.1, 126.1, 125.8 (q, ³J_CF = 3.6 Hz), 125.1, 124.2, 124.0 (q, ³J_CF = 3.8 Hz), 123.0, 121.6, 118.8, 116.6, 116.3, 114.9, 55.6, 21.2. HRMS (ESI) calcd for C₄₃H₃₅F₃N₃O₂S⁺: m/z = 714.2402. Found: m/z = 714.2401 [(MH)⁺]. Anal. Calcd for C₄₃H₃₄F₃N₃O₂S: C, 72.35; H, 4.80; N, 5.89. Found: C, 72.39; H, 5.16; N, 5.58.

[2x-Me]NO₃: MeOH/H₂O/THF (136 mL, 5:1:1 v/v/v) solution containing N,N-bis(4-methoxyphenyl)-3,5-dimethyl-4-(5-(6-(3-(trifluoromethyl)phenyl)-[2,2'-bipyridin]-4-yl)thiophen-2-yl)aniline (0.140 g, 0.196 mmol), Ru(trimethoxycarbonylterpy)Cl₃ (0.121 g, 0.196 mmol) and N-ethylmorpholine (0.25 mL) was sparged for 10 min with dinitrogen. Following a 16 h reflux, AgNO₃ (0.125 g, 0.735 mmol) was added to the reaction flask, and the resulting mixture refluxed for an additional 1.5 h. The mixture was cooled to room temperature and the solvent removed in vacuo. The resulting oil was solubilized in CH₂Cl₂/MeOH (19 : 1) and purified by column chromatography (Al₂O₃: CH₂Cl₂/MeOH, 19 : 1, Rf : 0.57) to yield 0.080 g (40%) of a fine, deep red solid. The identity of the compound was confirmed by ¹H NMR and HRMS (ESI) calcd for C₆₄H₅₀F₃N₆O₈RuS⁺: m/z = 1221.2406. Found: m/z = 1221.2410 [(M)⁺] and was used without further characterization.

[2x]NO₃: compound 2x-Me (0.050 g, 0.0409 mmol) was dissolved in a DMF/H₂O/NEt₃ (6 mL, 3:1:1 v/v/v) solution and refluxed overnight. The solvent was then removed under reduced pressure, and the resultant solid was washed successively with Et₂O, pet. ether and CH₂Cl₂ to yield 0.042 g (88%) of the product as a black microcrystalline solid. ¹H NMR (300 MHz, d₄-MeOD): δ = 9.23 (s, 2H, H_E), 9.00 (s, 2H, H_D), 8.83 (d, 1H, ⁴J = 1.2 Hz, H_e), 8.77 (d, 1H, ³J = 8.2 Hz, H_d), 8.66 (s, 1H, H_m), 8.21-8.19 (m, 2H, H_f, H_n), 7.94 (t, 1H, ³J = 7.8 Hz, H_c), 7.62-7.56 (m, 4H, H_A, H_B), 7.50 (d, 1H, ³J = 5.0 Hz, H_a), 7.15 (t, 1H, ³J = 6.3 Hz, H_b), 7.09-7.05 (m, 5H, H_g, H_k), 6.91 (d, 4H, ³J = 9.0 Hz, H_j), 6.74 (d, 1H, ³J = 7.9 Hz, H_p), 6.69 (s, 2H, H_i), 5.88 (d, 1H, ³J = 7.9 Hz, H_q), 3.81 (s, 6H, H_l), 2.70 (s, 6H, H_h). LRMS (MALDI-TOF) calcd for C₆₁H₄₄F₃N₆O₈RuS⁺: m/z = 1179.2. Found: m/z = 1179.2 [(M)]⁺. Anal. Calcd for C₆₁H₄₄F₃N₇O₁₁RuS4□H₂O: C, 57.87; H, 4.29; N, 7.87. Found: C, 58.00; H, 4.29; N, 7.80.