Synthesis and application of new β-amino alcohols based on the octahydro-cyclopenta[b]pyrrole system in the catalytic enantioselective addition of diethylzinc to benzaldehyde
摘要:
Starting from an industrial waste material, the synthesis of a series of new, artificial beta-amino alcohol structures (all-R)-6-10 and 13-16 based on the octahydrocyclopenta[b]pyrrole system is presented. These structures were also the subject of studies aimed at developing effective catalysts for enantioselective alkylation by diethylzinc. Attention was focussed on stereochemical and steric aspects of the catalyst (-precursor) structure. Potent chiral ligands have been developed reaching excellent enantioselectivities, e.g. op-values up to 99% with predominant formation of the (R)-configurated alkylation products. (C) 1997 Elsevier Science Ltd.
Enantioselective Catalytic Borane Reduction of Prochiral Ketones: Synthesis and Application of New Rigid β-Amino Alcohols with a Cycloalkanol Subunit
摘要:
Enantiocontrolled reduction of prochiral ketones with borane in the presence of new enantiomerically pure bi- and tricyclic beta-sec-amino alcohols 2-5 as stereodifferentiating catalysts afforded the optically active corresponding secondary alcohols in moderate to excellent (up to 98 % op) optical yields.