Catalysts containing lutetium

These intramolecular hydroaminations lead to the formation of chiral products. Thus, several studies have been devoted to developing ligands for enantioselective, intramolecular hydroaminations of olefins catalyzed by lanthanide complexes. ° Selectivities of these reactions with chiral cyclopentadienyl derivatives have been modest. Selectivities have been higher with catalysts containing non-cyclopentadienyl ligands. Some of tlie most selective catalysts are the yttrium complexes of the bis(thiolate) ligands reported by Livinghouse, the scandium and lutetium complexes of 33 -disubstituted binaphtholates reported by Hultzsch, and the BINAM-based bisamidates of Schafer.- A representative cyclization catalyzed by a member of each of these classes of catalyst are shown in Equation 16.64. 

Ytterbium and lutetium ionic complexes, derived from enantiopure substituted (R)-binaphthylamine ligands of the general formula [Li(THF) ][Ln[(f )C2oHi2(NR)2]2], have been investigated as catalysts for hydroamination/cyclization of several unsatu- rated amines CH2=CH(CH2) C(R2)CH2NH2 (n = 1 or 2). Complexes with isopropyl or cyclohexyl substituents on nitrogen atoms were found to be efficient catalysts for the formation of N-containing heterocycles under mild conditions with enantiomeric excesses up to 78%.124... 

Towards the end of the second millennium, studies of the transition elements continued to make major contributions to chemical science and technology. The development of new catalysts and reagents represents one area of activity. Examples are provided by the activation of saturated hydrocarbons by rhodium or lutetium complexes, new syntheses of optically active products in reactions which employ chiral metal compounds, and transition metal compounds which catalyse the stereospecific polymerization of alkenes. The ability of transition metal centres to bind to several organic molecules has been exploited in the construction of new two- and three-dimensional molecular architectures (Figure 1.4). New materials containing transition elements are being developed, one... 

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