1219938-71-2Relevant academic research and scientific papers
Bis(?5:?1-pentafulvene)titanium complexes: Catalysts for intramolecular alkene hydroamination and reagents for selective reactions with N'H acidic substrates
Janssen, Thomas,Severin, Rene,Diekmann, Mira,Friedemann, Marion,Haase, Detlev,Saak, Wolfgang,Doye, Sven,Beckhaus, Ruediger
, p. 1806 - 1817 (2010)
Intramolecular catalytic hydroamination reactions of geminally disubstituted amino alkenes employing the bulky substituted bis(? 5:?1-pentafulvene)titanium complexes 1a and 1b and the corresponding benzannelated derivative 2 as catalysts are presented. While all three complexes are competent hydroamination catalysts, best results are achieved with the bis(benzofulvene) derivative 2. In addition, a series of Ti'N-containing compounds became available by stoichiometric reactions of 1 with N'H acidic substrates. In such a way, using aniline derivates (H 2N'Ar, Ar: p-tolyl, 1-naphthyl) the bisamides (?5-C 5H4'CHR2)2Ti(NHAr)2 (CHR2: adamantyl, Ar: p-tolyl 5a; R: p-tolyl, Ar: p-tolyl 5b; R: p-tolyl, Ar: 1-naphthyl 5c; CHR2: adamantyl, Ar: 1-naphthyl 5d) are prepared in high yields under mild conditions. In contrast to this, the employment of the catalytically relevant amine H2NCH 2C(Ph)2CH2CH-CH2 (3a) in a reaction with (?5:?1-C5H4-CR 2)2Ti (CR2: adamantylidene, 1a) leads to the titanium monoamide (?5:?1-C5H 4-CR2)(?5-C5H4'CHR 2)Ti(NHCH2C(Ph)2CH2CH-CH 2) (6), characterized by X-ray diffraction. In reaction of 1a and 1b with benzophenone imine the titanocene bis(enamides) (?5-C 5H4'CHR2)2Ti(N-CPh2) 2 7a and 7b are formed. Titanium nitrogen double bonds are formed by treatment of 1a with 1,1-diphenylhydrazine. In that manner the hydrazido titanocene (?5-C5H4'CHR2) 2Ti-N'N(Ph)2 (CHR2: adamantyl) was structurally characterized as the pyridine adduct 9. Three different Ti'N bonds are formed in one step by reaction of (?5:?1-C5H 4-CR2)2Ti (R: p-tolyl, 1b) with 1,1-diphenylhydrazine and pyridine (py), leading to (?5-C 5H4'CHR2)Ti(-N'NPh2)('N'NPh 2)py 10b (dative Ti'N bond: Ti'py 2.211(2) ?, single Ti'N bond: Ti'NNPh2' 1.968(2) ?, double Ti'N bond: Ti'NNPh 22' 1.738(1) ?). The formation of 10b is accompanied by the liberation of one C5H5CHR2 ligand. Generally, the bis(?5:?1-pentafulvene)titanium complexes 1 and 2 are valuable catalysts in hydroamination reactions and reagents in order to prepare Ti'N-containing metallocene-type derivatives.
