Synthesis and coordination chemistry of chelate ligands containing cyclopentadienyl, indenyl and fluorenyl donors - Diastereoselectivity and NMR structure analysis

The functionalised oxetane O(CH2)(2)C(CH2Br) (CH2OMs) (1) is transformed in to tripod ligands ROCH2C(CH2PPh2)-(CH2PR'(2))(CH2Cp#) (R = H, SiMe3; R' = P h, Et; Cp# = indenyl, fluorenyl) (4) in a few steps. Epichlorohydrin O(CH2) CH(CH2Cl) (5) allows for diastereoselective one-pot syntheses of the Cp-fun ctionalised chelate ligands (Cp#CH2)C(H)OH(CH2PPh2) (Cp-# = Cp, indenyl, fl uorenyl) (6). The SiMe3-protected derivatives of these ligands react with R uCl2(PPh3)(3) to produce (Me3SiOCH(CH2-eta (1)-PPh2) (CH2-eta (5)-Cp#)Ru(PP h3) (Cl)) (Cp# = Cp, indenyl) (15) with high diastereoselective preference. With the same starting material, tripod Ligands 4 form Me3SiOCH2C(CH2-eta (1)-PPh2)(CH2-eta (1)-PPh2)(CH2- eta (5)-Indenyl)RuCl (R = Ph, Et) (16). As shown by complete NMR spectroscopy based structure analyses (DG methods) o f 16, the formation of 16 (R = Et) is diastereoselective. The only diastere omer which is observed is the one in which the PEt2, donor and the phenylen e part of the indenyl ligand are juxtaposed. In addition to quantitative NM R spectroscopy structure analyses, traditional analytical techniques, inclu ding X-ray analyses, were used to confirm the results.