Diisopropylcyanamide

Synthesis of aryl amidines¹⁾: To a vial Pd(O₂CCF₃)₂ (13.3 mg, 0.04 mmol), 6-methyl-2,2’-bipyridyl (10.2 mg, 0.06 mmol) and methanol (3.0 mL) are added and the mixture is stirred for 5 min before addition of diisopropylcyanamide (1 mmol), trifluoroborate (1.1 mmol) and trifluoroacetic acid (228 mg, 2 mmol) is added to the reaction mixture and the vial is instantly capped under air and then heated using microwave irradiation at 120 °C for 20 min. The reaction mixture is then diluted with 20 mL NaHCO₃ aq. and washed with 20 mL DCM. The organic phase is further extracted with 2 x 20 mL NaHCO₃ aq. The combined aqueous phases are basified to pH ~ 14 by the addition of NaOH and extracted with 3 x 60 mL DCM. The combined organic phases are dried and concentrated to provide the pure isolated product.

Synthesis of 2-aminopyridines by the [2+2+2] cycloaddition²⁾: FeI₂ (7.8 mg, 0.025 mmol) and dppp (21.2 mg, 0.05 mmol) are weighed in the glovebox and placed in a dried Schlenk tube. Subsequenly, distilled THF (2 mL) is added. The resulting mixture is stirred at room temperature for 30 min to afford an orange-yellow clear solution, at which time Zn dust (3.3 mg, 0.05 mmol) is added. After an additional 30 min of stirring, diyne 1 (0.5 mmol) is added followed by diisopropylcyanamide (2.5 mmol), and the mixture is stirred for 24 h. The solvent is evaporated, and the crude product is directly purified by silica gel flash column chromatography to give 2 in 83% yield.