Whitby group

To a 30 mL Schlenk vial under argon at room temperature was added dppf (68.1 mg, 0.13 mmol), sodium propane-2-thiolate (0.51 g, 5.0 mmol), PhBr (0.21 g, 1.3 mmol) and BnNC (0.22 mL, 2.0 mmol). PdCl₂ (12.8 mg, 0.072 mmol) was then added against a counterflow of argon. Finally, toluene (13 mL) was used to wash all solids from the sides of the vial, which was then heated at 109 °C in a Stem block. The reaction mixture was allowed to cool to room temperature before ether (10 mL) and concentrated aqueous potassium hydroxide solution (5 mL) were added. The aqueous layer was extracted with ether (3x15 mL). The combined organics were dried over MgSO₄, filtered and evaporated. Further purification on silica with petrol:ether (4:1) gave the title compound as a pale-yellow oil, (0.13 g, 40%), found to consist of two isomers by NMR in a ratio of 1 : 2.

To a 30 mL Schlenk vial under argon at room temperature was added dppf (66.8 mg, 0.13 mmol), sodium propane-2-thiolate (0.50 g, 5.0 mmol), PhBr (0.20 g, 1.3 mmol) and n-BuNC (0.20 mL, 2.0 mmol). PdCl₂ (12.5 mg, 0.072 mmol) was then added against a counterflow of argon. Finally, toluene (13 mL) was used to wash all solids from the sides of the vial, which was then heated at 109 °C in a Stem block for 5 h. The reaction mixture was allowed to cool to room temperature before ether (10 mL) and concentrated aqueous potassium hydroxide solution (5 mL) were added. The aqueous layer was extracted with ether (3x15 mL). The combined organics were dried over MgSO₄, filtered and evaporated. Further purification on silica with petrol:ether (2:1) gave the title compound as a pale-yellow oil, (0.19 g, 62%), found to consist of two isomers in a ratio of 3.7 : 1 by NMR.

Reaction 23b: Palladium-Catalytic synthesis of N-(tert-butyl)-N [1-phenyl-1-tetrahydro-1H-1-pyrrolylmethylidene]amine

Reaction 31B: Synthesis by tert-butyl deprotection of phenyl(tetrahydro-1H-1-pyrrolyl)methanimine

Dry Cs₂CO₃ (0.81 g, 2.5 mmol), dppf (0.11 g, 0.20 mmol),4-bromoacetophenone (0.40 g, 2.0 mmol) and morpholine (0.73 g, 0.010 mol) were added to a 30 mL Schlenk tube under argon. Dry, de-gassed toluene (10 mL) was added, followed by ^tBuNC (0.34 mL, 3.0 mmol) and finally PdCl₂ (19.8 mg, 0.11 mmol) was added against a flow of argon. Another aliquote of toluene (10 mL) was added and the tube fitted with a stopper. The mixture was heated with stirring at 109 °C for 5 h. After cooling to room temperature, the reaction mixture was added to ether (20 mL) and the resulting slurry was filtered and extracted with dilute acetic acid (2.5% in water, 6x5 mL). The combined aqueous extractions were washed with ether (2x10 mL), then treated with a concentrated KOH-solution (30 mL) in presence of ether (20 mL). The ethereal layer was collected and the aqueous layer extracted with ether (3x30 mL). The combined ether phases were dried over MgSO₄ before evaporation. Work-up followed by Kugelrohr-distillation gave the title compound as yellow crystals, (0.35 g, 62%), m.p. 102-104 ^oC.

Dry Cs₂CO₃ (0.84 g, 2.6 mmol), dppf (0.11 g, 0.20 mmol), 3-bromopyridine (0.32 g, 2.0 mmol) and pyrrolidine (0.73 g, 0.011 mol) were added to a 30 mL Schlenk tube under argon. Dry, de-gassed toluene (10 mL) was added, followed by ^tBuNC (0.34 mL, 3.0 mmol) and finally PdCl₂ (19.6 mg, 0.11 mmol) was added against a flow of argon. Another aliquote of toluene (10 mL) was added and the tube fitted with a stopper. The mixture was heated with stirring at 109 °C for 5 h. After cooling to room temperature, the reaction mixture was added to ether (20 mL) and the resulting slurry filtered to give a dark-brown solution which was extracted with dilute acetic acid (2.5% in water, 6x5 mL). The combined aqueous extractions were washed with ether (2x10 mL), then treated with a concentrated KOH-solution (30 mL) in presence of ether (20 mL). The ethereal layer was collected and the aqueous layer extracted with ether (3x30 mL). The combined ether phases were dried over MgSO₄ before evaporation. Kugelrohr-distillation (oven temp 105-110 ^oC / 1 mmHg) gave the title compound as a transparent oil which crystallised in the freezer to give a white solid, (0.33 g, 71%), m.p. 28-30 ^oC