1328993-72-1Relevant academic research and scientific papers
Asymmetric catalytic intramolecular hydroamination of aminoallenes by tantalum amidoalkoxide complexes
Hansen, Michelle C.,Heusser, Carolyn A.,Narayan, Tarun C.,Fong, Kristine E.,Hara, Nagiko,Kohn, Alexander W.,Venning, Alexander R.,Rheingold, Arnold L.,Johnson, Adam R.
experimental part, p. 4616 - 4623 (2011/12/03)
A series of tantalum complexes of chiral bidentate amidoalkoxide ligands was prepared. The crystal structure of one complex, Ta(NMe2) 3[-OCPh2CH(CHMe2)N(c-C6H 11)-] was obtained. Unlike previously described titanium complexes with these ligands, which are dimeric with bridging oxygen atoms, this tantalum complex is monomeric with an approximate trigonal-bipyramidal geometry. The resulting complexes were examined for their in situ activity for catalytic asymmetric hydroamination/cyclization of an aminoallene. Enantioselectivities up to 80% ee were observed for the cyclization of 6-methylhepta-4,5-dienylamine to 2-(2-methylpropenyl)pyrrolidine at 135 °C with 5 mol % catalyst loading.
