106044-85-3Relevant academic research and scientific papers
Highly enantioselective epoxidation of α,β-unsaturated esters by chiral dioxirane
Wu, Xin-Yan,She, Xuegong,Shi, Yian
, p. 8792 - 8793 (2002)
This paper describes a highly enantioselective epoxidation of α,β-unsaturated esters using the fructose-derived ketone 2 as catalyst and Oxone as oxidant. High ee's have been obtained for a number of trans and trisubstituted substrates (82-98% ee). The results described show that it is feasible for dioxiranes to effectively epoxidize electron-deficient olefins with high ee's. Copyright
Catalytic asymmetric epoxidation of α,β-unsaturated esters using an yttrium-biphenyldiol complex
Kakei, Hiroyuki,Tsuji, Riichiro,Ohshima, Takashi,Shibasaki, Masakatsu
, p. 8962 - 8963 (2005)
We succeeded in a catalytic asymmetric epoxidation reaction of α,β-unsaturated esters via a conjugate addition of an oxidant using 2-10 mol % of the yttirium-chiral biphenyldiol catalyst. A variety of substrates with β-aryl and β-alkyl substituents were epoxidized efficiently, yielding the corresponding α,β-epoxy esters in up to 97% yield and 99% ee. Copyright
Design and characterization of mechanism-based inhibitors for the tyrosine aminomutase SgTAM
Montavon, Timothy J.,Christianson, Carl V.,Festin, Grace M.,Shen, Ben,Bruner, Steven D.
, p. 3099 - 3102 (2008/12/22)
The synthesis and evaluation of two classes of inhibitors for SgTAM, a 4-methylideneimidazole-5-one (MIO) containing tyrosine aminomutase, are described. A mechanism-based strategy was used to design analogs that mimic the substrate or product of the reaction and form covalent interactions with the enzyme through the MIO prosthetic group. The analogs were characterized by measuring inhibition constants and X-ray crystallographic structural analysis of the co-complexes bound to the aminomutase, SgTAM.
Chemoenzymatic approach to optically active phenylglycidates: Resolution of bromo- and iodohydrins
Anand, Naveen,Kapoor, Munish,Koul, Surrinder,Taneja, Subhash C.,Sharma, Rattan L.,Qazi, Ghulam N.
, p. 3131 - 3138 (2007/10/03)
Enantiomerically enriched phenylglycidates, precursors of the taxol C-13 phenylisoserine side chain and diltiazem, were prepared by kinetic resolution of anti-2-bromo-3-hydroxy- and anti-3-hydroxy-2-iodophenylpropanoates to provide enantioriched (2R,3R)- and (2S,3S)-halohydrins. The bulkiness and inflexibility of bromo and iodo groups in halohydrins have made them inaccessible to the active site of most of the lipases utilized for the hydrolysis of their acyloxy derivatives. In a set of 22 hydrolases screened herein, including native as well as commercial enzymes, only Aspergillus niger (Lipase AS, AMANO) could catalyze the hydrolysis with high enantioselectivity (E = 176). The resolved halohydrins easily underwent transformation to the corresponding (2S,3R)- and (2R,3S)-phenylglycidates.
A catalytic asymmetric synthesis of chiral glycidic acid derivatives through chiral dioxirane-mediated catalytic asymmetric epoxidation of cinnamic acid derivatives
Imashiro, Ritsuo,Seki, Masahiko
, p. 4216 - 4226 (2007/10/03)
A novel and practical asymmetric synthesis of chiral glycidic acid derivatives involving methyl (2R,3S)-3-(4-methoxyphenyl)glycidate ((2R,3S)-2a), a key intermediate for diltiazem hydrochloride (1), was developed. Treatment of methyl (E)-4-methoxycinnamate ((E)-3a) with chiral dioxirane, generated in situ from a catalytic amount (5 mol %) of an 11-membered C2-symmetric binaphthyl ketone (R)-7a, provided (2R,3S)-2a in 92% yield and 80% ee. Other cinnamic acid esters and amides were epoxidized by the use of the same procedure to give the corresponding chiral glycidic acid derivatives with up to 95% yield and 92% ee. Higher enantioselectivities in the asymmetric epoxidation of (E)-cinnamates than that of (E)-stilbene derivatives were observed and were proposed to be attributed to a dipole-dipole repulsion between oxygen atoms of an ester group in the cinnamates and those of the lactone moieties in the binaphthyl dioxirane.
Facile synthesis of (2R,3S)-3-(4-methoxyphenyl)glycidic esters via optical resolution of the unisolated labile free acid
Yamamoto,Hayashi,Masaki,Nohira
, p. 403 - 406 (2007/10/02)
(,3S)-3-(4-Methoxyphenyl)glycidic esters were efficiently synthesized by the optical resolution of the racemic acid and esterification of the optically active acid thus obtained, in the form of its alkali metal salt.
