13368-65-5Relevant articles and documents
Highly enantioselective copper(I)-phosphoramidite-catalysed additions of organoaluminium reagents to enones
Alexakis, Alexandre,Albrow, Victoria,Biswas, Kallolmay,D'Augustin, Magali,Prieto, Oscar,Woodward, Simon
, p. 2843 - 2845 (2005)
Simple phosphoramidite ligands afford good to excellent levels of enantioselectivity in 1,4-additions of AIR3 species to enones; sequential carboalumination-ACA cascades are possible. The Royal Society of Chemistry 2005.
Asymmetric hydrogenation of substituted 2-pyrones
Fehr, Matthias J.,Consiglio, Giambattista,Scalone, Michelangelo,Schmid, Rudolf
, p. 5768 - 5776 (1999)
Various substituted 2-pyrones have been hydrogenated with high enantioselectivity (up to 97% ee) to the corresponding 5,6-dihydropyrones using cationic ruthenium catalysts containing the (6,6'-dimethoxybiphenyl- 2,2'diyl)bis[3,5-di(tert-butyl)phenylphosphine] ligand. When substituents at position 3 are absent, 5,6-dihydropyrones are further hydrogenated to the fully saturated δ-lactones. In the case of 4,6-dimethyl-2H-pyran-2-one, the diastereoselectivity of the second hydrogenation step was determined by the chirality of the applied catalyst, while for the 4,5,6-trimethyl-2H-pyran2- one a double asymmetric induction effect was observed. Other cyclic substrates with endo- or exocyclic double bonds were hydrogenated, although with substantially lower enantioselectivity with respect to the 2-pyrones.
Scalemic β-amino sulfide ligands: Use in enantioselective conjugate additions and X-ray analysis of a dimeric copper(I) complex
Cran, Graeme A.,Gibson, Colin L.,Handa, Sheetal,Kennedy, Alan R.
, p. 2511 - 2514 (1996)
The enantioselective conjugate addition using a number of scalemic β-amino sulfide ligands to achieve enantiomeric excesses of up to 64% are described together with the X-ray absolute structure analysis of a dimeric copper(I) complex.
Total Synthesis of (+)-Sarcophytin
Nannini, Leonardo J.,Nemat, Suren J.,Carreira, Erick M.
, p. 823 - 826 (2018)
A total synthesis of the cembranoid (+)-sarcophytin is presented, featuring a Diels–Alder cycloaddition of an enone as the dienophile with an ester-derived dienoate. The study highlights a peculiar geometric preference for the Z dienoate to furnish the cy
CATALYTIC ASYMMETRIC SYNTHESES II. HYDROGENATION OF α,β-UNSATURATED KETONES USING CHIRAL RUTHENIUM COMPLEXES
Massonneau, Viviane,Maux, Paul Le,Simonneaux, Gerard
, p. 269 - 274 (1987)
α,β-Unsaturated ketones have been hydrogenated in the presence of HRuCl(TBPC)2 (TBPC) = (-)-trans-1,2-bis(diphenylphosphinomethyl)cyclobutane) to give ketones with a maximum optical purity of 62percent.Factors affecting the stereoselectivity of the catalytic reaction are discussed.
Counterion Enhanced Organocatalysis: A Novel Approach for the Asymmetric Transfer Hydrogenation of Enones
Scharinger, Fabian,Márk Pálv?lgyi, ádám,Zeindlhofer, Veronika,Schnürch, Michael,Schr?der, Christian,Bica-Schr?der, Katharina
, p. 3776 - 3782 (2020/06/22)
We present a novel strategy for organocatalytic transfer hydrogenations relying on an ion-paired catalyst of natural l-amino acids as main source of chirality in combination with racemic, atropisomeric phosphoric acids as counteranion. The combination of a chiral cation with a structurally flexible anion resulted in a novel chiral framework for asymmetric transfer hydrogenations with enhanced selectivity through synergistic effects. The optimized catalytic system, in combination with a Hantzsch ester as hydrogen source for biomimetic transfer hydrogenation, enabled high enantioselectivity and excellent yields for a series of α,β-unsaturated cyclohexenones under mild conditions. Moreover, owing to the use of readily available and chiral pool-derived building blocks, it could be prepared in a straightforward and significantly cheaper way compared to the current state of the art.
Asymmetric Baeyer-Villiger oxidation: Classical and parallel kinetic resolution of 3-substituted cyclohexanones and desymmetrization of: Meso -disubstituted cycloketones
Wu, Wangbin,Cao, Weidi,Hu, Linfeng,Su, Zhishan,Liu, Xiaohua,Feng, Xiaoming
, p. 7003 - 7008 (2019/07/31)
Regioselectivity is a crucial issue in Baeyer-Villiger (BV) oxidation. To date, few reports have addressed asymmetric BV oxidation of 3-substituted cycloketones due to the high difficulty of controlling regio- and stereoselectivity. Herein, we report the asymmetric BV oxidation of 3-substituted and meso-disubstituted cycloketones with chiral N,N′-dioxide/Sc(iii) catalysts performed in three ways: classical kinetic resolution, parallel kinetic resolution and desymmetrization. The methodology was applied in the total and formal synthesis of bioactive compounds and natural products. Control experiments and calculations demonstrated that flexible and adjustable catalysts played a significant role in the chiral recognition of substrates.
