Preparation of (η5-C5H5)2Ti alkyl compounds and reactions with unsaturated substrates

Frontier Elements: Connections with f-Elements

“…With acetonitrile, CH3CN, Cp*2TiR (R =CH3, C6H5, CH2CH=CH2) react giving initial adduct formation followed by insertion (R = C6H5, CH2CH=CH2) and coupling (R = CH3) reactions, very similar to what has been observed for various Cp2TiR compounds [6,9,11].…”

“…For R = alkyl, aryl the thermal decomposition of the compounds was studied in some detail [8,9,22]. Relevant for our discussion here is that the same stoichiometry is found; RH formation is quantitative 2:…”

“…CO, CO2, CS2, isonitriles, nitriles, ketones, acetylenes). Most of the work has been published and the interested reader is referred to these publications for detailed information [5][6][7][8][9][10][11].…”

“…(1) R = alkyl, alkenyl; M = Li [9,10] R = allyl or substituted allyl; M = MgX [12] R = benzyl, aryl; M = MgX [13] The compounds are monomeric, 15 el compounds that tend to achieve coordinative saturation by reaction with solvent molecules, appropriate donor ligands or otherwise (e.g., with allyl ligands η 3 -coordination is observed). The compounds are extremely air-sensitive, and many of them are thermally labile (decomposing around or below room temperature, Table 1), and expose a high reactivity with respect to many reagents.…”

Structure of a scandium–carboxylate complex: (η5-C5Me5)2Sc(O2C)C6H4CH3

“…The insertion of CO 2 into the scandium-aryl bond is reminiscent of CO2 reactivity with organoaluminium reagents (Ziegler, 1956), and is more facile than with analogous titanium reagents, e.g. Cp2TiR, R = alkyl (Klei, Telgen & Teuben, 1981).…”