Intramolecular hydroamination of aminoallenes is catalyzed by titanium complexes with a number of chiral amino alcohols. The ring-closing reaction of hepta-4,5-dienylamine at 110 °C with 5 mol % catalyst gives a mixture of 6-ethyl-2,3,4,5-tetrahydropyridine (14-33%) and both Z-and E-2-propenylpyrrolidine (67-86%). However, the ring-closing reaction of 6-methylhepta-4,5-dienylamine at 135 °C with 5 mol % catalyst gives exclusively 2-(2methylpropenyl)pyrrolidine. The pyrrolidine products are obtained with enantiomeric excesses up to 16%.
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