furan; methyllithium in tetrahydrofuran T=-78°C;

pyridine; phosphorus tribromide in diethyl ether -30 deg C, 2 h, then 20 deg C, 3 h;

1: 65 percent 2: 63 percent / PBr3, pyridine / diethyl ether / -30 deg C, 2 h, then 20 deg C, 3 h View Scheme

sodium tetrahydroborate; tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran T=20°C; 20 h; further reducing agents; Product distribution;

1: (i) EtMgBr, (ii) CuCl, THF, (iii) /BRN= 1816644/ 2: PBr3, Py / diethyl ether 3: (i) EtMgBr, THF, (ii) CuCN, (iii) /BRN= 1817884/ View Scheme

1: 87 percent / copper(I) iodide, sodium carbonate, tetra-n-butylammonium chloride / dimethylformamide / 23 h / 20 °C 2: 86 percent / CBr4, PPh3 / CH2Cl2 / 1.5 h / 0 °C 3: 51 percent / copper(I) iodide, sodium carbonate, tetra-n-butylammonium chloride / dimethylformamide / 23 h / 20 °C 4: 73 percent / H2, H2N(CH2)2NH2 / Ni(OAc)2*4H2O, NaBH4 / ethanol View Scheme

lithium triethylborohydride; tetrakis(triphenylphosphine) palladium(0)

sodium tetrahydroborate; tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran T=20°C; 20 h; further reducing agents; Product distribution;