1-piperidinecarboxaldehyde T=160 - 170°C; 64 h;

potassium carbonate in N,N-dimethyl-formamide T=70°C;

hydrogen; dirhodium tetraacetate; triphenylphosphine in ethyl acetate P=20685.9 Torr; Further byproducts given;

T=90°C; Arylation; 2 h;

1: Et3N / CH2Cl2 2: 70 percent / 2 h / 90 °C View Scheme

1: With sulfuric acid; acetic acid T=120°C; 2 h; 2: With water Cooling with ice;

formic acid; nickel T=80°C;

ammonia; hydrogen; nickel in methanol T=50°C; P=3750.3 Torr; 4 h;

1: tetrahydrofuran; toluene / 3 h / Heating 2: 34 percent / toluene / 15 h / Ambient temperature 3: H2, NaOH, Et3N, Ti(OiPr)4 / Ru(OAc)2<(S)-BINAP> / methanol; CH2Cl2 / 170 h / 30 °C / 75006 Torr 4: aq. HCl / 5.5 h / Heating 5: 29 percent / PPh3, Et3N, CCl4 / acetonitrile / 15 h / Ambient temperature 6: 92 percent / 1N NaOH / ethanol / 4 h / 60 °C View Scheme

1: tetrahydrofuran; toluene / 3 h / Heating 2: 34 percent / toluene / 15 h / Ambient temperature 3: H2, NaOH, Et3N, Ti(OiPr)4 / Ru(OAc)2<(S)-BINAP> / methanol; CH2Cl2 / 170 h / 30 °C / 75006 Torr 4: aq. HCl / 5.5 h / Heating View Scheme