TITLE:
Chiral Camphor-Based 1,3- and 1,4-Amino Alcohols and Aminodiols as Ligands for Diethylzinc Addition to Aldehydes
AUTHORS:
Olusegun B. Olubanwo, James A. Golen, Arnold L. Rheingold, Vesa Nevalainen
KEYWORDS:
Ligand, Enantioselective, Amino Alcohol, Aminodiols, (+)-Camphor
JOURNAL NAME:
International Journal of Organic Chemistry,
Vol.8 No.2,
June
22,
2018
ABSTRACT: Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13),
and (1R,2S,2’R,4R)-1,7,7-trimethyl-2-piperidin-2-ylmethyl-bicyclo[2.2.1]heptan-2-ol (19b)
from commercially available (d)-camphor
(1) are described. Key steps of the syntheses involved substrate-controlled diastereoselective alkylation
and platinum oxide-catalyzed hydrogenation reactions. These compounds,
and other intermediate amino alcohols in their syntheses, were successfully
utilized as ligands in enantioselective diethyl zinc (Et2Zn)
addition to benzaldehyde with moderate enantioselectivity.