Access to Highly Enantioenriched Donepezil-like 1,4-Dihydropyridines as Promising Anti-Alzheimer Prodrug Candidates via Enantioselective Tsuji Allylation and Organocatalytic Aza-Ene-Type Domino Reactions
摘要:
This work aims at exploiting both the enantioselective Tsuji allylation of allyl carbonate 6 and an organocatalytic aza-ene-type domino reaction between enal 3a and beta-enaminone 4a to develop a straightforward access to all of the four possible stereoisomers of a donepezil-like 1,4-dihydropyridine 1a (er up to 99.5:0.5; overall yield up 64%), an anti-Alzheimer's prodrug candidate. This strategy was extended to the preparation of other enantioenriched 1,4-dihydropyridines 1b-i (eight examples), highlighting its potential in the development of these chiral AChE inhibitors.
A Method for the Preparation of β-Amino-α,β-unsaturated Carbonyl Compounds: Study of Solvent Effect and Mechanism
作者:Reyno R. S.、Akash Sugunan、Ranganayakulu S.、Cherumuttathu H. Suresh、Goreti Rajendar
DOI:10.1021/acs.orglett.9b04531
日期:2020.2.7
An efficient method for the preparation of β-amino-α,β-unsaturated carbonylcompounds is demonstrated. Bench-stable sodium 3-oxo-enolates were prepared from carbonylcompounds, and reacted with amines in the presence of an acid and a desiccant. DFT studies revealed contrasting mechanisms toward the reactivity of aliphatic amines in protic solvents and aromatic amines in aprotic solvents. While the