bis-triphenylphosphine-palladium(II) chloride; N-ethyl-N,N-diisopropylamine in N,N-dimethyl-formamide T=70 - 80°C;

1: 1.) LDA / 1.) THF, from -78 deg C to -60 deg C, 45 min, 2.) THF, from -78 to RT, overnight 2: 51 percent / n-Bu4NF / tetrahydrofuran; various solvent(s) View Scheme

<b>Multi-step reaction with 5 steps<br /> </b>1: 94 percent / tetra-n-butylammonium hydrogen sulfate, sodium hydroxide / CH₂Cl₂ / 2 h / Ambient temperature<br />2: 98 percent / Br₂ / CCl₄ / 4 h / Ambient temperature<br />3: 1.) t-butyllithium / 1.) THF, pentane, -90 deg C, 5 min, 2.) from -90 deg C to room temp., overnight<br />4: 22 percent / peracetic acid, acetic acid, sodium acetate / CH₂Cl₂ / 1.) 0 deg C, 4 h, 2.) room temp., 7 days<br />5: 84 percent / 2,6-di tert-butyl-4-methylpyridine / CH₂Cl₂ / 1.) 0 deg C , 1 h, 2.) room temp., 3 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>1: 94 percent / tetra-n-butylammonium hydrogen sulfate, sodium hydroxide / CH₂Cl₂ / 2 h / Ambient temperature<br />2: 98 percent / Br₂ / CCl₄ / 4 h / Ambient temperature<br />3: 1.) t-butyllithium / 1.) THF, pentane, -90 deg C, 5 min, 2.) from -90 deg C to room temp., overnight<br />4: 22 percent / peracetic acid, acetic acid, sodium acetate / CH₂Cl₂ / 1.) 0 deg C, 4 h, 2.) room temp., 7 days<br />5: 84 percent / 2,6-di tert-butyl-4-methylpyridine / CH₂Cl₂ / 1.) 0 deg C , 1 h, 2.) room temp., 3 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 95 percent / pyridine / diethyl ether / 1 h / 0 &deg;C<br />2: 53 percent / CuBr₂ / CHCl₃; ethyl acetate / 12 h / Heating<br />3: Et₃N / CHCl₃; ethyl acetate / 2 h / 0 &deg;C<br />4: 84 percent / 2,6-di tert-butyl-4-methylpyridine / CH₂Cl₂ / 1.) 0 deg C , 1 h, 2.) room temp., 3 h<br /> <br /> &nbsp;