A chiral pool-derived calcium catalyst for intramolecular hydroamination with enhanced enantioselectivity

The synthesis of (2S,3S)-3-methyl-2-(methyl(pyridin-2-yl-methyl)amino)-1,1-diphenylpentan-1-ol 5 and its use together with [Ca(N(SiMe3)2)2(thf)2] 6 as in situ generated catalytic system in the enantioselective intramolecular hydroamination of 2,2-diphenylpent-4-en-1-amine 7 as benchmark substrate is discussed. Enantiomeric excesses of up to 77 %, the highest yet reported for calcium-based systems, as well as significantly shortened reaction times while only requiring 5 mol-% of catalyst, were achieved.