Intramolecular Hydroaminations of Aminoalkynes Catalyzed by Yttrium Complexes and Aminoallenes Catalyzed by Zirconium Complexes

摘要

It was demonstrated that Y[N(TMS)2]3,the neutral yttrium-diamine complex 13 and yttrium-NPS complexes 15 are efficient precatalysts for intramolecular hydroamination of aminoalkynes involving primary amines.Complex 13 and 15 were quantitatively prepared in situ by direct metalation of the ligands 4 and 9 with 1 equiv of Y[N(TMS)2]3 in benzene-d_6 at 120 °C for 5 days and 10 days,respectively,via elimination of(TMS)2NH.5-Exo-and 6-exo-dig intramolecular hydroamination of aminoalkynes using catalyst 12 and 13 proceeded smoothly to give nitrogen-contained cyclic products in good to excellent yields in all cases.In the case of 7-exo-dig intramolecular hydroamination,the desired product was produced in 41% and 48% yields despite the gem-dimethyl effect.However,treatment of catalyst 15 with aminoalkynes(19 and 22)having a methyl substituent at the carbon adjacent to triple bond and 6-exo-dig intramolecular hydroamination of 21 failed to give the desired products.Zirconium-catalyzed intramolecular hydroamination of aminoallenes(25,27,and 31)with 5 mol% 16 afforded 2-(trans-1-propenyl)pyrrolidine,2-isopropylenepyrrolidine,and 2-(trans-1-propenyl)piperidine in 96%,95%,and 93% yield,respectively.However,subjecting 25 to 5 mol% 15 was unsuccessful to produce the desired product.