Ethers diphenylprolinol methyl

Diphenylprolinol methyl ether catalyses the enantioselective Michael addition of simple aldehydes to simple enones.219... 

Diphenylprolinol methyl ether (145) catalyses intermolecular Michael addition of simple aldehydes to enones in the absence of solvents with high enantioselectivities (95-99% ee) and significantly lower catalyst loadings (5 mol%) than have been typical in this arena.175... 

Chi Y, Gellman SH (2005) Diphenylprolinol methyl ether a highly enantioselective catalyst for Michael addition of aldehydes to simple enones. Qrg Lett 7 4253 1256... 

Scheme 7.28 Asymmetric Michael addition of aldehydes with methyl or ethyl vinyl ketones catalysed hy (S)-diphenylprolinol methyl ether.

Chi YG, Gelhnan SH (2005) Diphenylprolinol Methyl Ether A Highly Enantioselective Catalyst for Michael Addition of Aldehydes to Simple Enones. Org Lett 7 4253... 

Frechet s group reported a similar cascade reaction but using two immobilized amino catalyst derivatives (Scheme 6.14) [40]. They found that the combination of two catalysts, the salt of unidazolidinone with polystyrene sulfonate 114 and polymer-supported diphenylprolinol methyl ether 115, efficiently catalyzed a MCR of two consecutive... 

Two C-C Bond-Forming Events In 2008, Frechet and coworkers described an impressive asymmetric cascade reaction promoted by soluble star polymers with core-confined catalytic entities [10]. The encapsulation of catalysts into soluble star polymers allowed the use of incompatible catalysts and prevented undesired interactions between these catalytic systems. The organocascade corresponded to a nucleophilic addition of Af-methylindole to a,p-unsaturated aldehydes followed by a Michael addition of the adduct to methylvinylketone (MVK) in the presence of H-bonding additive (Scheme 12.5). Each catalyst - imidazolidinone 8 for the nucleophilic addition and diphenylprolinol methyl ether 9 for the Michael addition - or their combination cannot mediate both reaction steps. In particular, p-toluenesulfonic acid (p-TSA) diminished the ability of the chiral pyrrolidine 9 to effect enamine activation. Therefore, p-TSA and 9 were encapsulated in the core of star polymers, which cannot penetrate each other. Imidazolidone 8 was added to the acid star polymer and diffused to the core to form the salt, which allowed the iminium activation and catalyzed the first step. The second step was catalyzed by the pyrrolidine star polymer in presence of the H-bonding additive 10, which... 

The (S)-diphenylprolinol-derived oxazabotohdine with an ethanediolated boron atom is a new catalyst for the as3fmmetric reduction of ketones with BH3 SMe2- 1,3-Cyclo-alkanediones undergo CBS-reduction to provide (3if)-hydroxycycloalkanones. Based on this method a very short synthesis of chiral estrone methyl ether is completed. ... 

In 2003, Melchiorre and Jprgensen found modest enantioselectivities in the first catalytic version of the direct enantioselective Michael addition of aldehydes to vinyl ketones catalyzed by the chiral amine (5)-2-[bis(3,5-dimethylphenyl)methyl] pyrrolidine (21) (Scheme 2.13) [34]. Further studies on the reaction carried out by different groups led to more efficient catalysts such as diphenylprolinol ethers 22a [35] and 22b [36] and imidazohdinone 23 [37] (Schane 2.13). The highest enantioselectivities reported to date (95-99% ee) have been obtained with catalyst 22b employing significantly lower catalyst loadings (1-5 mol%) than those reported with other organocatalysts (20-30 mol%)[36]. 

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