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Thiol Esters (thiol + ester)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Enantioselective Organocatalytic Conjugate Addition of Aldehydes to ,,,-Unsaturated Thiol Esters

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009
Shaolin Zhu
Abstract The first example of an organocatalytic asymmetric Michael addition of aldehydes to ,,,-unsaturated thiol esters promoted by chiral diphenylprolinol silyl ether is presented. The reaction occurs with good yields, diastereoselectivity and excellent enantioselectivity. [source]

Preparation of the ,3 -Homoselenocysteine Derivatives Fmoc- ,3hSec(PMB)-OH and Boc- ,3hSec(PMB)-OH for Solution and Solid-Phase-Peptide Synthesis and Selenoligation

HELVETICA CHIMICA ACTA, Issue 9 2007
Oliver Flögel
Abstract The title compounds, 4 and 7, have been prepared from the corresponding , -amino acid derivative selenocystine (1) by the following sequence of steps: cleavage of the SeSe bond with NaBH4, p -methoxybenzyl (PMB) protection of the SeH group, Fmoc or Boc protection at the N-atom and Arndt,Eistert homologation (Schemes,1 and 2). A ,3 -heptapeptide 8 with an N-terminal ,3 -hSec(PMB) residue was synthesized on Rink amide AM resin and deprotected (,in air') to give the corresponding diselenide 9, which, in turn, was coupled with a ,3 -tetrapeptide thiol ester 10 by a seleno-ligation. The product ,3 -undecapeptide was identified as its diselenide and its mixed selenosulfide with thiophenol (Scheme,3). The differences between , - and , -Sec derivatives are discussed. [source]

Enantioselective Organocatalytic Conjugate Addition of Aldehydes to ,,,-Unsaturated Thiol Esters

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009
Shaolin Zhu
Abstract The first example of an organocatalytic asymmetric Michael addition of aldehydes to ,,,-unsaturated thiol esters promoted by chiral diphenylprolinol silyl ether is presented. The reaction occurs with good yields, diastereoselectivity and excellent enantioselectivity. [source]

Tin-Free Radical Carbonylation of Alkylsulfonyl Derivatives into Alkylcarbonyl Derivatives

CHEMISTRY - AN ASIAN JOURNAL, Issue 8-9 2008
Sangmo Kim
Abstract A simple radical approach based on tin-free radical carbonylation is devised for the direct conversion of alkylthiosulfonates, alkylsulfonyl cyanides, and alkylsulfonyl oxime ethers into the corresponding alkyl thiol esters, acyl cyanides, and acylated oxime ethers in a single step. The present approach is very simple, highly efficient, and minimizes the formation of byproducts. [source]