Hydroamination of 2-vinylpyridine, styrene, and isoprene with pyrrolidine catalyzed by alkali and alkaline-earth metal complexes

The complexes (dpp-bian)Mg(thf)3, (dpp-bian)Ca(thf)4 and (dpp-bian)Mg(pyr)3 (dpp-bian is the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene dianion; pyr is the pyrrolidine) catalyze the addition of pyrrolidine to 2-vinylpyridine at room temperature. The compound (dppbian)Mg[N(SiMe3)2] containing a dpp-bian radical anion catalyzes the addition of pyrrolidine to styrene at 60 °C. The dpp-bian radical anion lithium-sodium salt [(dpp-bian)Li{N-(SiMe3)2}][Na(C7H8)] is an active catalyst of the addition of pyrrolidine to styrene and isoprene at 60 °C. In all the case, the content of the catalyst was from 1 to 2 mol.%. For styrene and 2-vinylpyridine, the reactions proceeded with the formation of anti-Markovnikov addition product, while 1,4-addition product was obtained in the case of isoprene.