The sequential reaction of selected polycyclic aromatic hydrocarbons with butyllithium/TMEDA/ hexane and sulfur allows preparation of ring-fused dithiins, dithioles, and thiophenes. In this manner, phenanthrene has been converted to phenanthro[4,5-~de][1,2]dithiin and phenanthro[l,IOc~-1,2dithiole. Yellow crystals of the dithiin form inoC2/c (#15) space group .with < = 4, a = 13.537(3) A, b = 8...

Seven new dihydrobenzofurans and 2 propynyl thiophenes were isolated from the roots of Eupatorium heterophyllum together with 13 known compounds. The compounds characterized using spectroscopic methods including 2D NMR, infrared, mass spectrometric techniques. Aerial parts this plant have been to contain various sesquiterpenoids displayed high chemical diversity (several and/or identified) amon...

The use of the congested aryl bromide 2-bromo-1,3-dichlorobenzene as coupling partner allows to modify the regioselectivity of the arylation of 3-substituted thiophene derivatives in favour of carbon C5. The coupling of this aryl bromide with a variety of 3-substituted thiophenes gave in all cases the desired 5-arylation products in moderate to good yields using only 0.5 mol % of a phosphine-fr...