138098-75-6Relevant academic research and scientific papers
Simple preparation of enantiomeric Michael adducts of thiophenol to chalcones: Easily available new chiral building blocks
Skarzewski, Jacek,Zielinska-Blajet, Mariola,Turowska-Tyrk, Ilona
, p. 1923 - 1928 (2001)
A facile and enantioselective method for the multigram preparation of the title compounds is described. The Michael addition of thiophenols to chalcones catalyzed by (+)-cinchonine, followed by crystallization, led to the corresponding adducts 2 in up to >95% e.e. The stereoselective Beckmann rearrangement of the oxime of (+)-1,3-diphenyl-3-phenylsulfanylpropan-1-one 2a gives the anilide of (R)-(+)-3-phenyl-3-phenylsulfanylpropanoic acid (as determined by X-ray analysis) and alcoholysis leads to the corresponding enantiomerically pure ethyl ester.
Rh-Catalyzed Asymmetric Hydrogenation of β-Substituted-β-thio-α,β-unsaturated Esters: Expeditious Access to Chiral Organic Sulfides
Liu, Gang,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
, p. 5636 - 5639 (2018/09/12)
Rh/bifunctional bisphosphine-thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydorgenation of both (Z)- and (E)-isomers of β-substituted-β-thio-α,β-unsaturated esters was successfully developed. This new asymmetric catalytic methodology provided highly efficient access to two enantiomers of chiral organic sulfides ethyl β-substituted-β-thio-propanoates with excellent results (up to 99% yield and >99% ee for (Z)-substrates, up to 99% yield and 98% ee for (E)-substrates, TON up to 5000), which are important intermediates in organic synthesis.
Chiral amino ether-controlled catalytic enantioselective arylthiol conjugate additions to α,β-unsaturated esters and ketones: Scope, structural requirements, and mechanistic implications
Nishimura, Katsumi,Tomioka, Kiyoshi
, p. 431 - 434 (2007/10/03)
Asymmetric conjugate addition reaction of 2-trimethylsilylbenzenethiol with enoates and enones is catalyzed by a chiral amino ether-lithium thiolate complex and affords adducts with high enantioselectivity. Both the s-cis conformation and a steric wall at one side of the carbonyl group are structural requirements in substrates yielding adducts with high enantioselectivity. Reactions with tert-butyl enones gave addition products with high enantioselectivity. Construction of two contiguous chiral centers was possible by this addition-protonation sequence. Methyl tiglate was stereoselectively converted to a single syn-adduct of 95% enantiomeric excess (ee) bearing two contiguous chiral centers. Methyl 2-phenyl-2-butenoate was converted to a single syn-adduct of 95% ee, which was desulfurized to methyl 2-phenylbutanoate of 95% ee. These additions generate a transient lithium enolate that is protonated by a thiol anti to the C-S bond, giving the corresponding product having two adjacent stereocenters.
A novel chemoenzymatic enantioselective synthesis of some clinically effective CNS drugs and related compounds
Kumar, Ashok,Ner, D H,Dike, Suneel
, p. 803 - 809 (2007/10/02)
We have demonstrated in this study a novel route for the synthesis of benzothiopyran and benzothiazepin ring systems along with the synthesis of optically pure, clinically effective drugs tomoxetine, fluoxetine and thiazesim.
