New indane derived aminoalcohols as chiral ligands for the catalytic enantioselective addition of diethylzinc to aldehydes
摘要:
Secondary amines react with (1R,2S)-indene oxide 1 in a completely regioselective manner leading to trans-2-dialkylamino-1-indanols 4a-d in high yield. A Mitsunobu inversion via the corresponding p-nitrobenzoates, followed by reduction with DIBALH leads to the cis-2-dialkylamino-1-indanols 5a-d also in high yield. These two new classes of aminoindanols have been tested as chiral ligands for the enantioselective addition of diethylzinc to both aliphatic and aromatic aldehydes, leading to 1-substituted 1-propanols with up to 80% e.e. A very simple procedure for the enantiomeric enrichment of 1 from 88% to greater than or equal to 99% e.e. is also reported. (C) 1997 Elsevier Science Ltd.