gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• substituent at nitrogen located in the opposite direction to the carbonyl group, while cisoid (cis 15a’ (16a’)) isomers featured a smaller substituent at nitrogen located in the opposite direction to the carbonyl group. We determined the quantitative ratio as well as the cis/trans configuration of isomers by

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• improvement of enantioselectivity and the ee values obtained by its copper(II) complex were satisfactory (75–96%). This phenomenon was more distinct in the case of the application complexes of ligands with cis-trans configuration (Ib vs IIb). Whilst the complex of Ib exhibited only poor enantioselectivity

Influence of the cis/trans configuration on the supramolecular aggregation of aryltriazoles

• Sara Tejera,
• Giada Caniglia,
• Rosa L. Dorta,
• Andrea Favero,
• Javier González-Platas and
• Jesús T. Vázquez

Beilstein J. Org. Chem. 2019, 15, 2881–2888, doi:10.3762/bjoc.15.282

• stabilization of the supramolecular aggregation of bis(4-bromophenyl)triazoles. The trans or cis spatial disposition of the triazole rings is highly important for gelation, with the cis configuration having higher propensity. Keywords: circular dichroism; cis/trans configuration; gels; triazole; X-ray

• (10), forming gels much easier than their corresponding β-anomers (trans). This showed that their ability to form gels was critically dependent on the cis/trans configuration present in the molecule. To confirm this result, the supramolecular properties of trans- and cis-1,2-bis(4-(4-bromophenyl)-1H

C-5’-Triazolyl-2’-oxa-3’-aza-4’a-carbanucleosides: Synthesis and biological evaluation

• Roberto Romeo,
• Caterina Carnovale,
• Salvatore V. Giofrè,
• Maria A. Chiacchio,
• Adriana Garozzo,
• Emanuele Amata,
• Giovanni Romeo and
• Ugo Chiacchio

Beilstein J. Org. Chem. 2015, 11, 328–334, doi:10.3762/bjoc.11.38

• synthesized compounds. In particular, compound 14d showed a high level of inhibitory activity with CC50 values of 5 μM for all the utilized cell lines, while compounds 13c, 13e, 13d, 14c, 14e, 14f and 14g show the same CC50 values only for HFF cells. Noteworthy, the relative cis, trans configuration of 13 and

The preparation of several 1,2,3,4,5-functionalized cyclopentane derivatives

• André S. Kelch,
• Peter G. Jones,
• Ina Dix and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 1705–1712, doi:10.3762/bjoc.9.195

• shown in 5 – all five substituents could point in the same direction (cis,cis,cis,cis-configuration). Alternatively, one (or more) of these functionalized groups could be directed in opposite directions (e.g. cis,cis,cis,trans-configuration, as in 7). Whether this stereochemical difference will have an

• failed so far, as is also shown in Scheme 3. Only in one case was a halogenated derivative obtained in poor yield: treatment of 16 with triphenylphosphine–bromine in carbon tetrachloride provided the tribromo ether derivative 19 as a minor component. Surprisingly, this had the cis,cis,cis,trans

• -configuration of the substituents at the five-membered ring, as was shown by single crystal X-ray analysis (Figure 1). It is unclear at the present time whether the correspondingly configurated pentaalcohol was already present in the starting material 16 as a side-product, which had been overlooked in previous

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones

• Nicole Zimmermann,
• Robert Hilgraf,
• Lutz Lehmann,
• Daniel Ibarra and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1246–1255, doi:10.3762/bjoc.8.140

• synthesis of the cis,trans dihydronepetalactone c, a cis,trans-configuration between the substituents at C5-C1 and C1-C2 of the cyclopentane backbone needed to be established. With acetate 16 as the key intermediate, a stereoselective “syn”-addition of hydrogen from the same side as the (R)-configured side

• acetoxymethyl group at C1), 5-CH3 and 2-H, 1’-H and 2-H as well as 5-H and 1’’-CH3 (protons of the methyl group at C1 of the side chain) which is in line with a cis,trans-configuration (using the nomenclature described above). Starting from 26, the synthesis of the cis,trans-dihydronepetalactone c was completed