CROWN ETHER-SUBSTITUTED INDENE AND 3,4-DIMETHYLCYCLOPENTADIENE

Several indene and cyclopentadiene derivatives have been synthesized, which are substituted with crown ethers, thereby creating ligands whos e heterotopic faces have the ability to function as ligands in both or ganometallic and coordination chemistry. The syntheses of mono- and bi s-N-3-indenylpropyl-substituted aza-12-crown-4 4, aza-15-crown-5 5, an d diaza-18-crown-6 6 ether compounds are described. However it was not possible to isolate stable eta5-bound metal complexes with 4, 5, or 6 . In an alternative approach 1-(2-aminoethyl)-3,4-dimethyl-cyclopenta- 1,3-diene (9) has been prepared from 3,4-dimethylcyclopent-2-enone (7) via Knoevenagel condensation, followed by reduction of the alpha,beta ,gamma,delta-unsaturated nitrile 8 with LiAlH4/AlCl3. CYClization of 9 produced the first example of crown ether-substituted cyclopentadiene s, 3,4-dimethylcyclopenta-1,3-dienyl)ethyl]aza-12-C-4 (10) (12-C-4-HCp ''), and as the result of a 2 + 2 addition, lcyclopenta-1,3-dienyl)eth yl]1,13-diaza-24-crown-8 (11) (24-C-8-HCp''2). Reaction of 10 with NaH , (CO)3W(CH3CN)3, and CH3I affords the eta5-bound complex (12-C-4-Cp'' )W(CO)3CH3 (12), which in turn can complex Na+ to give 13 (=(12)2.Na+B Ph4-).