1,4-Benzoxathiane, 2- or 3-substituted, is an important scaffold, and despite its presence in several therapeutic agents, it is chemically unexploited. Furthermore, only a few examples in literature report this moiety in its enantiopure form. Here, taking advantage to the formation of diastereomeric amides by using (S)-phenylethylamine, which show significant differences in terms of H-nuclear magnetic resonance (NMR) spectra and other physical chemical properties, we defined for the first time the absolute configuration of each amide, both 2- or 3-substituted. Moreover, the diastereomeric amides were further hydrolyzed in acid conditions, letting to the achievement of the corresponding 1,4-benzoxathian carboxylic acids.
In this work, we exploit the electronic features of tetrathiafulvalene (TTF) as a backbone in synthesizing chiral derivatives. The aim is to make use of TTF's well-known and unique redox and semiconducting properties in the fields of enantio-selective recognition and chiral charge transfer (CT) complex preparation, with the ultimate objective of obtaining devices with various potential applications, ranging from plasmonics to quantum computing. In particular, both cyclohexane-bis (TTF-amide)-based enantiomers 1-(S,S) and 1-(R,R), stable under an oxidation regime, have been selected, and under these conditions, the electrochemical enantiospecific response of the four possible systems, coming from the combination with L- and D-tartaric acid, respectively, was tested.
In this work, we report an efficient approach to 2-oxoazetidine-3-carboxylic acid derivatives based on a thermally promoted Wolff rearrangement of diazotetramic acids in the presence of nucleophiles. The method allows easy variation of the substituent in the exocyclic acyl group by introducing different -, -, and -nucleophilic reagents into the reaction. The reaction of chiral diazotetramic acids leads exclusively to -diastereomeric β-lactams.
School of Pharmacy and Pharmaceutical Sciences, Panoz Institute and Trinity Biomedical Sciences Institute, Trinity College Dublin, 152 - 160 Pearse St, Dublin 2, D02 R590, Ireland. Electronic address:
Biocatalysis is a valuable industrial approach in active pharmaceutical ingredient (API) manufacturing for asymmetric induction and synthesis of chiral APIs. Herein, we investigated synthesis of a panel of microtubule-destabilising antiproliferative β-lactam enantiomers employing a commercially available immobilised Candida antarctica lipase B enzyme together with methanol and MTBE. The β-lactam ring remained intact during chiral kinetic resolution reactions, plausibly due to a bulky N-1 phenyl substituent on the β-lactam ring substrate.
Heating -butyl-tetraline with [(-cymene)RuCl] produces the racemic complex [(arene)RuCl], which can be separated into enantiomers by chromatography of its diastereomeric adducts with chiral phosphine ligand. The resolved chiral complex catalyzes C-H activation of -methoxy-benzamides and their annulation with -vinyl-pivaloyl amide giving dihydroisoquinolones in 50-80% yields and with 40-80% enantiomeric excess.
A diastereomeric mixture of racemic 3-phthalimido--lactam / was synthesized by the Staudinger reaction of carboxylic acid activated with 2-chloro-1-methylpyridinium iodide and imine . The amino group at the C3 position of the -lactam ring was used for further structural upgrade. --lactam ureas were prepared by the condensation reaction of the amino group of -lactam ring with various aromatic and aliphatic isocyanates.
