Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• intramolecular esterification gave the cyclized products 74 and 75 in 82% yield with a 5:1 ratio of anti/cis diastereomers accompanied by a dimeric byproduct 76 in 2.5% yield. The anti-diastereomer with cis-PhO and Me groups as major product 74 is attributed to the stereoelectronic effect between the n-orbital

• of the etheric oxygen atom and the antibonding orbital of the P=O bond (the stereoelectronic effect), leading to the more stable anti-diastereomer 74 (Scheme 16) [38]. In the phostone 74 was installed a linker 2-(5-aminopentoxy) group via transesterification with benzyl N-(5-hydroxypentyl)carbamate

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• , trifluoromethyl radicals and its longer-chain analogues, share a common electrophilic character and a stabilizing stereoelectronic effect [14], we envisioned that the “dummy group” methodology could be translated into the formation of sought after perfluoroalkyl radicals (Scheme 1). In this work, we report the

Polarity effects in 4-fluoro- and 4-(trifluoromethyl)prolines

• Vladimir Kubyshkin

Beilstein J. Org. Chem. 2020, 16, 1837–1852, doi:10.3762/bjoc.16.151

• conformation. An electron-withdrawing substituent tends to adopt an axial position due to an orbital effect called the gauche-effect (stereoelectronic effect) [67][68]. Conversely, a bulky substituent adopts an equatorial position (steric effect) [69][70]. At the same time, there has been no evidence that a

Investigation of the role of stereoelectronic effects in the conformation of piperidones by NMR spectroscopy and X-ray diffraction

• Cesar Garcias-Morales,
• David Ortegón-Reyna and
• Armando Ariza-Castolo

Beilstein J. Org. Chem. 2015, 11, 1973–1984, doi:10.3762/bjoc.11.213

• –H(7)eq), a type of hyperconjugative interaction. Keywords: NMR spectroscopy; piperidone; spin–spin coupling constant; stereoelectronic effect; X-ray diffraction structure; Introduction Stereoelectronic effects have attracted the attention of many researchers with an interest in organic chemistry

• intermolecular hydrogen bond N(3)–H(3)∙∙∙O(28). The D∙∙∙A distance is 3.186(3) Å and the N(3)–H(3)∙∙∙O(28) angle is 160 ± 2°. Compound 7 formed chains of molecules by N(3)–H(3)∙∙∙O(22) hydrogen bonds with a D∙∙∙A distance of 3.261(3) Å and a N(3)–H(3)∙∙∙O(28) angle of 162 ± 1°. Stereoelectronic effect analysis σ

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• higher adsorption strength on the cathode surface. This suggests that dienes undergo carboxylation according to mechanism II while adsorbed on the surface, combined with mechanism I (Scheme 7). Moreover it was shown that diene configuration has a strong stereoelectronic effect on the rate of the

De novo macrolide–glycolipid macrolactone hybrids: Synthesis, structure and antibiotic activity of carbohydrate-fused macrocycles

• Richard T. Desmond,
• Anniefer N. Magpusao,
• Chris Lorenc,
• Jeremy B. Alverson,
• Nigel Priestley and
• Mark W. Peczuh

Beilstein J. Org. Chem. 2014, 10, 2215–2221, doi:10.3762/bjoc.10.229

• macrocycle relative to the pyranose. The exo-anomeric effect is a stereoelectronic effect concerned with the donation of electron density from a lone pair on the aglycone oxygen (O2) into the σ* antibonding orbital of the O12–C1 bond. Figure 3e and Figure 3f show the Newman projections for the glycosidic

• work, however, relates the role of the exo-anomeric effect on the low-energy conformation of macrocycles linked through an anomeric center. This weak stereoelectronic effect should be listed with other factors such as ring size, multi-atom planar units, and stereogenic centers as determinants of

Electron and hydrogen self-exchange of free radicals of sterically hindered tertiary aliphatic amines investigated by photo-CIDNP

• Martin Goez,
• Isabell Frisch and
• Ingo Sartorius

Beilstein J. Org. Chem. 2013, 9, 437–446, doi:10.3762/bjoc.9.46

• ) and triisopropylamine (TIPA). The hindrance is due to a stereoelectronic effect with DABCO [21], and due to overcrowding with TIPA [22]. As sensitizers, we have chosen 9,10-anthraquinone (AQ) on one hand and xanthone (XA) or benzophenone (BP) on the other; with triethylamine, these are typical

Flexible synthetic routes to poison- frog alkaloids of the 5,8-disubstituted indolizidine- class I: synthesis of common lactam chiral building blocks and application to the synthesis of (-)-203A, (-)-205A, and (-)-219F

• Naoki Toyooka,
• Dejun Zhou,
• Hideo Nemoto,
• H. Martin Garraffo,
• Thomas F. Spande and
• John W. Daly

Beilstein J. Org. Chem. 2007, 3, No. 29, doi:10.1186/1860-5397-3-29

• , The methyl or vinyl anion then attacks from the α-orientation controlled by a stereoelectronic effect [19] producing the desired trisubstituted piperidine as a single isomer. This argument can also be explained by the Cieplak's hypothesis [20] as shown in Figure 3. Reduction of the ester moiety in 7