AN EASY ROUTE TO 1-GERMAINDENES VIA A TRANSMETALATION ZIRCONIUM GERMANIUM REACTION

Several 1-zirconaindenes (4) have been obtained easily by heating phen ylmethylzirconocene with various symmetrical (R = R' = CH3, C2H5, n-C3 H7, Si(CH3)3 and unsymmetrical (R = CH3, R' = Si(CH3)3) alkynes (R - C = C - R'). Under similar experimental conditions, the ynamine, diethy laminotrimethylsilylethyne, led to a regioselective reaction. From the X-ray structure of the zirconaindene product, the trimethylsilyl grou p was found close to the zirconium atom. Compounds 4 with germanium te trachloride afford new 1-germaindenes (7), characterized by H-1 and C- 13 NMR and mass spectrometry, in good yield.