Sterically encumbered chiral amino alcohols for titanium-catalyzed asymmetric intramolecular hydroamination of aminoallenes
摘要:
A variety of sterically encumbered amino alcohol ligands were prepared in a two-step modular synthesis. The titanium complexes of these ligands were prepared in situ and used as catalysts for hydroamination. The intramolecular hydroamination of 6-methyl-hepta-4,5-dienylamine at 135 degrees C with 5 mol % catalyst gave exclusively 2-(2-methyl-propenyl)-pyrrolidine with enantiomeric excesses up to 16%. (C) 2009 Elsevier Ltd. All rights reserved.
Sterically encumbered chiral amino alcohols for titanium-catalyzed asymmetric intramolecular hydroamination of aminoallenes
摘要:
A variety of sterically encumbered amino alcohol ligands were prepared in a two-step modular synthesis. The titanium complexes of these ligands were prepared in situ and used as catalysts for hydroamination. The intramolecular hydroamination of 6-methyl-hepta-4,5-dienylamine at 135 degrees C with 5 mol % catalyst gave exclusively 2-(2-methyl-propenyl)-pyrrolidine with enantiomeric excesses up to 16%. (C) 2009 Elsevier Ltd. All rights reserved.