Holmium complexes, reaction with

The chiral holmium(III)-complex-catalysed Diels-Alder cycloaddition of siloxyvinylindoles (70) with e-deficient olefins (71) formed exo-substituted hydro-carbazoles (72) in up to 99% yield and 94% ee. Alkylation of these cycloadducts gave tricyclic compounds (73) with four continuous chiral centres (Scheme 20). The thermal 4-i-2-cycloaddition reaction of 7-substituted 4-styrylcoumarins with A-phenylmaleimide and tetracyanoethylene in nitrobenzene yielded 3,4-annulated coumarins. The thermal Diels-Alder cycloaddition of ( )-l,3-dihydro-3-phenacylidene-2//-indol-2-ones (74) with l,2-dihydro-2-oxospiro[3//-indole-3,2 -[2H,9a//-pyrido[2,l-fe][l,3]oxazines]] (75) produced complex dispirooxindoline fused [l,3]oxazines (76) with high regio- and stereo-selectivity (Scheme 21). " ... 

Isopropylcyclopentadienyl complexes of lanthanum, neodimium and holmium are used for the synthesis of heterogenic catalysts of the Fisher-Tropsch reaction [118]. For this purpose the silicon oxide containing OH groups on the surface is treated with a THF solution of (i-C3H7C5H4)3Ln. This leads to the fixation of REM ions on the surface of the carrier. Organic groups are removed by heating in vacuum and then the catalyst is doped with palladium. 

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