Enantioselective Iridium-Catalyzed α-Allylation with Aqueous Solutions of Acetaldehyde
作者:Tobias Sandmeier、Erick M. Carreira
DOI:10.1021/acs.orglett.9b04658
日期:2020.2.7
The enantioselective α-allylation of aqueous solutions of acetaldehyde using iridium- and amine-catalyzed substitution of racemic allylicalcohols is described. The method utilizes a readily available, safely handled aqueous solution of acetaldehyde and furnishes γ,δ-unsaturated aldehydes in good yields and greater than 99% enantiomeric excess. The synthetic potential of the method is demonstrated
Efficient enantioselective synthesis of (-)-sugiresinol dimethyl ether was accomplished based upon two asymmetric induction processes: asymmetric beta-alkylation of alpha,beta-unsaturated aldimines and enantioselective dihydroxylation of olefins.
Enantioselective total synthesis of the di-O-methyl ethers of (–)-agatharesinol, (+)-hinokiresinol and (–)-sugiresinol, characteristic norlignans of Coniferae
enantioselective syntheses of the di-O-methyl ethers of the norlignans, (–)-agatharesinol (–)-1a, (+)-hinokiresinol (+)-2a and (–)-sugiresinol (–)-3a are described. Grignard addition of vinylmagnesium bromide to an aldimine (–)-13, prepared from the tert-butyl ester 11 and 4-methoxycinnamaldehyde 12, afforded a homochiral vinyl aldehyde, (–)-3-(4-methoxyphenyl)pent-4-enal (–)-14 in >95% ee, which was converted