13448-80-1Relevant articles and documents
Enantioselective addition of dimethylzinc to α-keto esters
Blay, Gonzalo,Fernandez, Isabel,Marco-Aleixandre, Alicia,Pedro, Jose R.
, p. 3754 - 3757 (2007)
The readily available (+)-N-Benzyl-(S)-mandelamide catalyzes the enantioselective addition of dimethylzinc to α-keto esters to give α-methyl-α-hydroxy esters containing stereogenic quaternary centers with moderate to good yields (56-87%). A good enantioselectivity of the reaction is obtained for aryl and heteroaryl keto esters. For these substrates ee values of 75-90% are obtained. The enantioselectivity is somewhat lower for the substrates bearing an aliphatic chain. Georg Thieme Verlag Stuttgart.
Multicenter Strategy for the Development of Catalytic Enantioselective Nucleophilic Alkylation of Ketones: Me2Zn Addition to α-Ketoesters
Funabashi, Ken,Jachmann, Markus,Kanai, Motomu,Shibasaki, Masakatsu
, p. 5489 - 5492 (2003)
An array of heteroatoms is essential for the activity and enantioselectivity of the catalyst 2 in the addition of Me2Zn to α-ketoesters 1 (e.g. see equation). α-Hydroxyesters 3 were obtained with up to 96% ee in the presence of a catalytic amount of additive iPrOH, which serves to generate the catalytically active monomeric species (based on the observation of nonlinear effects).
Isothiourea-Catalyzed Acylative Kinetic Resolution of Tertiary α-Hydroxy Esters
Greenhalgh, Mark D.,Laina-Martín, Víctor,Neyyappadath, Rifahath M.,Qu, Shen,Smith, Andrew D.,Smith, Samuel M.
, p. 16572 - 16578 (2020/09/09)
A highly enantioselective isothiourea-catalyzed acylative kinetic resolution (KR) of acyclic tertiary alcohols has been developed. Selectivity factors of up to 200 were achieved for the KR of tertiary alcohols bearing an adjacent ester substituent, with both reaction conversion and enantioselectivity found to be sensitive to the steric and electronic environment at the stereogenic tertiary carbinol centre. For more sterically congested alcohols, the use of a recently-developed isoselenourea catalyst was optimal, with equivalent enantioselectivity but higher conversion achieved in comparison to the isothiourea HyperBTM. Diastereomeric acylation transition state models are proposed to rationalize the origins of enantiodiscrimination in this process. This KR procedure was also translated to a continuous-flow process using a polymer-supported variant of the catalyst.
Enantioselective addition of organozinc reagents to carbonyl compounds catalyzed by a camphor derived chiral γ-amino thiol ligand
Wu, Hsyueh-Liang,Wu, Ping-Yu,Cheng, Ying-Ni,Uang, Biing-Jiun
, p. 2656 - 2665 (2016/05/10)
In this article, the design and synthesis of the chiral camphor derived γ-amino thiol ligand 17 and its application in catalytic enantioselective carbon-carbon forming reactions through the addition of organozinc reagents to carbonyl compounds is described. The catalytic activity and enantioselectivity of ligand 17 is demonstrated in the enantioselective addition of various organozinc reagents to aldehydes and ketoesters, offering the corresponding alcohols in high yields and enantioselectivities. The role of the mercapto group in the highly enantioselective 1,2-addition reaction of organozincs to aldehyde is also discussed.
Asymmetric Ti-crossed Claisen condensation: Application to concise asymmetric total synthesis of alternaric acid
Nagase, Ryohei,Oguni, Yumiko,Ureshino, Satoko,Mura, Hiroaki,Misaki, Tomonori,Tanabe, Yoo
, p. 7001 - 7003 (2013/09/02)
Asymmetric Ti-crossed Claisen condensation utilizing the dioxane-2,5-dione chiral template and its successful application to total synthesis of chiral alternaric acid are described.
