764650-90-0Relevant academic research and scientific papers
Harnessing the Power of the Asymmetric Grignard Synthesis of Tertiary Alcohols: Ligand Development and Improved Scope Exemplified by One-Step Gossonorol Synthesis
Gilheany, Declan G.,Kavanagh, Saranna E.
supporting information, p. 8198 - 8203 (2020/11/18)
A series of N-substituted cyclohexyldiaminophenolic ligands for the asymmetric Grignard synthesis of tertiary alcohols is reported. The 2,5-dimethylpyrrole-decorated ligand led to improved enantioselectivities and broadened the scope of the methodology. As an exemplar, we report an unprecedented highly selective one-step synthesis of gossonorol in 93% ee, also constituting the shortest formal syntheses of natural products boivinianin B and yingzhaosu C.
Light-Enabled Enantiodivergence: Stereospecific Reduction of Activated Alkenes Using a Single Organocatalyst Enantiomer
Hostmann, Theresa,Molloy, John J.,Bussmann, Kathrin,Gilmour, Ryan
supporting information, p. 10164 - 10168 (2019/12/24)
Light-enabled enantiodivergence is demonstrated in which the alkene substrate configuration is manipulated (E → Z) prior to organocatalytic reduction with a chiral thiourea and Hantzsch ester. This allows stereodivergent reduction to be regulated at the substrate level with high fidelity and mitigates the need for a second, enantiomeric catalyst (up to 93:07 and 95:5 er). The synthetic utility of this strategy has been demonstrated in the synthesis of the weight-loss drug (R)-Lorcaserin (Belviq) and a potent AMPA modulator.
Synthesis and characterization of novel chiral bidentate P,N-containing ligands and ruthenium(II) complex. the application in asymmetric transfer hydrogenation of ketones
Zeng, Li,Wu, Fang,Li, Yan-Yun,Dong, Zhen-Rong,Gao, Jing-Xing
supporting information, p. 34 - 39 (2014/05/20)
Novel chiral bidentate P,N-containing ligands have been easily synthesized by Schiff-base condensation of o-(diphenylphosphino)benzaldehyde and modified chiral diamine, (R,R)-2-(2,5-dimethyl-pyrrol-1-yl)-cyclohexylamine, further reduction with NaBH4. The chiral ruthenium(II) complex could be successfully prepared from the reaction between chiral bidentate aminophosphine ligand and RuCl2(PPh3)3. The chiral bidentate P,N-containing ligands and ruthenium(II) complex were fully characterized by NMR, IR, HRMS and single-crystal X-ray diffraction studies. In the presence of KOH, the asymmetric transfer hydrogenation (ATH) of various ketones catalyzed by the chiral ruthenium(II) complex proceeded smoothly under mild conditions, affording corresponding chiral secondary alcohols with up to 99% conversion and up to 60% ee. Additive such as NH4I was found to be helpful to promoting the enantioselectivity.
Organocatalytic asymmetric transferhydrogenation of β-nitroacrylates: Accessing β2-amino acids
Martin, Nolwenn J. A.,Cheng, Xu,List, Benjamin
supporting information; experimental part, p. 13862 - 13863 (2009/02/06)
We describe a highly efficient and enantioselective Hantzsch ester mediated conjugate reduction of β-nitroacrylates that is catalyzed by a Jacobsen thiourea catalyst as a key step in a new route to optically active β2-amino acids. Copyright
Organocatalytic asymmetric transfer hydrogenation of nitroolefins
Martin, Nolwenn J. A.,Ozores, Lidia,List, Benjamin
, p. 8976 - 8977 (2008/02/10)
We describe a highly efficient and highly enantioselective Hantzsch ester mediated conjugate transfer hydrogenation of β,β-disubstituted nitroolefins that is catalyzed by a Jacobsen-type thiourea catalyst. Copyright
Enantioselective thiourea-catalyzed acyl-Mannich reactions of isoquinolines
Taylor, Mark S.,Tokunaga, Norihito,Jacobsen, Eric N.
, p. 6700 - 6704 (2007/10/03)
(Chemical Equation Presented) Inexpensive aromatic feedstocks are substrates for highly enantioselective acylative Mannich reactions catalyzed by a thiourea chiral hydrogen-bond donor 1. This methodology provides access to useful 1-substituted dihydroisoq
Highly enantioselective catalytic acyl-Pictet-Spengler reactions
Taylor, Mark S.,Jacobsen, Eric N.
, p. 10558 - 10559 (2007/10/03)
The enantioselective cyclization of N-acyliminium ions generated in situ from tryptamine is promoted with high enantioselectivity by a new chiral thiourea catalyst. This represents the first successful system for asymmetric catalysis of the Pictet-Spengle
