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.
Palladium-Catalyzed Intermolecular Oxidative Coupling Reactions of (<i>Z</i>)-Enamines with Isocyanides through Selective β-C(sp<sup>2</sup>)-H and/or C=C Bond Cleavage
two efficient palladium‐catalyzed intermolecular oxidative couplingreactions of (Z)‐enamines with isocyanides via selective β‐C(sp2)‐H and/or C=C bond cleavage have been developed, leading to controllable chemodivergent and stereoselective construction of a wide range of (E)‐β‐carbamoylenamine derivatives containing strong intramolecular hydrogen bonds. Furthermore, possible reaction pathways for these
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
(Z)-Enaminones are easily synthesized from poorly nucleophilic anilines and 4-methoxy-3-buten-2 one (an effective and inexpensive surrogate for 3-butyn-2-one) with impressive “on water” acceleration.
Ruthenium Complexes of Electronically Coupled Cyclopentadienone Ligands – Catalysts for Transformations of Propargyl Alcohols
作者:Edgar Haak
DOI:10.1002/ejoc.200700064
日期:2007.6
A series of donor- and acceptor-substituted rutheniumcyclopentadienonecomplexes were synthesized and their catalytic activities towards propargylalcohols focused on amination reactions have been investigated. It is shown that the substituents of the cyclopentadienoneligand determine the mode of activation of propargylalcohols by these complexes leading to different central intermediates in catalytic
Ruthenium-Catalyzed Enaminoketone Formation from Propargyl Alcohols
作者:Edgar Haak
DOI:10.1055/s-2006-947357
日期:2006.8
Monomeric ruthenium(O) complexes containing electronicallycoupled dienone ligands were found to catalyze the formation of enaminoketones from propargylalcohols.