[BMIM(SO3H)][OTf]; 1-n-butyl-3-methylimidazolium hexafluorophosphate T=75°C; Nazarov Cyclization; 4 h; Schlenk technique;

8-methylquinoline 1-oxide; {1,3-bis[2,6-di(propan-2-yl)phenyl]-1,3-dihydro-2H-imidazol-2-ylidene}AuCl; AgNTf2 in 1,2-dichloro-ethane T=80°C; 0.8 h; Inert atmosphere;

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -60 °C 1.2: tetrahydrofuran; hexane / -78 - -40 °C 2.1: anhydrous potassium carbonate / methanol / 20 °C 3.1: 49 percent / triethylamine; DMAP / CH2Cl2 / 20 °C 4.1: HgCl2 / CH2Cl2 / 1.5 h / 20 °C 4.2: 99 percent / p-TsOH*H2O / CH2Cl2; methanol View Scheme

toluene-4-sulfonic acid in toluene T=100°C; Nazarov cyclization; 10 h;

formic acid; (trimethylsilyl)manganese pentacarbonyl; phosphoric acid 1.) Et2O, 5 kbar, 2.) 90 deg C, 2 h; Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;

PPA