Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• modifications of amidyl radicals aimed at optimizing their polarity via electronic effects, which may enhance their effectiveness in hydrogen abstraction from electron-deficient substrates. Additionally, strategies to optimize steric effects could improve their regioselectivity in hydrogen abstraction from

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• first reacted with diethyl 3-phenyl-1-(4-toluene)sulfonylaziridine-2,2-dicarboxylate (1a), affording cis-oxazolidines 3aa–aj in 43–84% yields and 37–98% ee. Obvious influences of electronic and steric effects on both the yields and enantioselectivities were observed. Aromatic aldehydes 2e and 2f with

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• in Py2MTM is increased 3000-fold. The nuclear spin of the nitrogen in PyBTM and Py2MTM can couple with the radical electron spin, leading to EPR spectra with hyperfine structure [58]. Effectively, the substitution in ortho-position has strong electronic as well as steric effects, allowing to tune the

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• in steering catalytic selectivity. In 2016, the Jiang group achieved regioselective control in the gold-catalyzed intramolecular hydroarylation of alkynes by modulating the electronic and steric effects of ligands (Scheme 2) [20]. Mechanistically, the electron-deficient phosphite ligand L1 and the

• features of the starting material. By exploiting preorganization, steric effects, or directing groups within the substrate, chemists can achieve high levels of regioselectivity, diastereoselectivity, and enantioselectivity without relying on external catalysts or additives. This approach has been

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• being more easily oxidizable than the initial THIQ-N-Boc. Conversely, increasing the amount of THF relative to acetonitrile had the opposite effect on the yield. The use of diisopropyl phosphite decreased the reaction yield, which is presumed to be due to its steric effects. Moreover, phosphorylation

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• cycloalkane (Figure 5), the preferred pucker is determined through a competition between hyperconjugation (e.g., σC–H → σ*C–F) and steric effects. For fluorocyclobutane (30) and fluorocyclohexane (32), the preferred conformation is the one in which fluorine is equatorial [48], with sterics playing the

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• attachment – a near two-fold decrease in yield was observed (H2a vs H2e), inferring that the reaction is strongly affected by steric effects. A high yield (78%) was also observed for the hydroxy-bearing hydantoin from threonine (H2g), suggesting that the reaction works smoothly in the presence of an electron

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• in solution. Although Me2B had the correct alignment of double bonds, meeting the Schmidt criteria, the reaction did not proceed under 405 nm excitation. This may be due to steric effects, a lack of molecular attraction, or an insufficient molar extinction coefficient at that wavelength. Me4B did not

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• organocatalyst C21. A considerable drop in yield and enantioselectivity was also observed in the reaction with dibenzylaniline. Interactions with and steric effects of the CPA C21 guiding the orientation of the substrates dictate the stereocontrol of the reaction. The utilization of CPA (R)-C23 in a dynamic

• 196a–k (Scheme 58) [88]. Both organocatalysts showed comparable effectivity in terms of enantioselectivity across. The difference between these catalysts becomes more visible through DFT calculations. In the case of biaryl phosphoric acid C30, stereocontrol is driven by the steric effects of the groups

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• K2CO3 at 55 °C to yield the corresponding products 62 in good to excellent yield (Scheme 25) [76]. It was observed that both electronic as well as steric effects on the aryl electrophile and phenol nucleophile were well tolerated. Further, this study was used for the one-pot synthesis of diaryl ethers

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• . This may also be due to crystal packing effects or the Ni(II) metal center [56][57], as well as the crystallization solvent [43]. It is not possible to ascertain whether steric effects of the β-ethyl and the anthracenyl carbons are causing the ruffling observed, and a full statistical model of a large

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• an electron-donating methoxy group on the phenyl substituent. Derivatives with a 3-OTBS side chain, 12c–e, displayed moderate diastereoselectivity, except for the higher diastereoselectivity achieved for 12f (dr 20:1), probably due to steric effects, albeit at the expense of a reduced isolated yield

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

• Hammett parameters account only for the electronic effect of substituents, much research has been devoted to develop physical-organic descriptors, which consider steric effects and separate the electronic effect into contributions from resonance and induction, among others [27][77][78][79][80][81]. In

• the change in predictive performance. Using this method, the authors observed that the main contribution towards enantioinduction by CPAs is through steric effects, in line with previous literature. Besides the establishment of experimental data sets, the number of ML data sets based on quantum

• also the structure for which the descriptors are considered. This can either be ensured by expert-knowledge of preselecting relevant structures, for example based on a known mechanism, or by considering information from the entire conformer ensemble. Parallel to the evolution in modelling steric

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• aromatic aldehydes (e.g., 2{1–3}) did not work in the GBB reaction (Figure 4). This result is in accordance with the previous findings [21]. Notably, steric effects were not significant since o,o′-disubstituted aldehydes (e.g., 2{4–6}) displayed usual efficiency. As might be expected from our previous

• performance in the parallel GBB reaction. (Hetero)aromatic aldehydes 2{1–6} illustrating electronic and steric effects on the parallel GBB reaction. Physicochemical properties of the chemical space of 271 Mln. members obtained by virtual GBB reaction (MW – molecular weight; HAcc/HDon – H-bond acceptor/donor

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• both C–F bonds in 17 and 19 enabled an additional σCH→σ*CF interaction, rather than the negligible σCF→σ*CF electron delocalization that would occur if these bonds were vicinally antiperiplanar. As discerned from the decomposition of the full electronic energy into Lewis (e.g., steric effects) and non

• -Lewis (electron delocalization) contributions, 17 and 19 were favored by a delicate equilibrium between weak repulsion and substantial stabilization due to hyperconjugation. Conversely, structures such as 9 and 10 experienced minimal steric effects but were inadequately stabilized by electron

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• reduction. This electrophilic aromatic substitution usually needs harsh reaction conditions, tedious synthetic procedures and sometimes encounters the trouble of separating positional isomers caused by orientation or steric effects of the pre-existed amino group on the aryl moiety. Nevertheless, anilines

Synthesis and physical properties of tunable aryl alkyl ionic liquids based on 1-aryl-4,5-dimethylimidazolium cations

• Stefan Fritsch and
• Thomas Strassner

Beilstein J. Org. Chem. 2024, 20, 1278–1285, doi:10.3762/bjoc.20.110

• , displayed a much lower viscosity, indicating that additional steric effects due to the 4-OCF3 substituent play a role for the viscosity of the TAAIL [48][49]. The viscosities of the NTf2 ionic liquids 37–63 at 25 °C are given in Table 2. In general, with increasing alkyl chain lengths we observe an

Domino reactions of chromones with activated carbonyl compounds

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1256–1269, doi:10.3762/bjoc.20.108

• the chromone and at carbon C-4 of the diene. However, in case of a benzyl and a benzyloxy group located at carbon C-4 of the diene, the overall yields were rather low (20%). This might be explained by steric effects. One of the best yields was obtained for the reaction of diene 6a with unsubstituted

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• Ar and CF3 groups can localize the negative charge and also provide steric effects to afford stereoselective cycloaddition products with 3:1 to 6:1 dr. The steric hindrance also prevents products 9 from undergoing a second cycloaddition. The control reactions of methyl ketone or benzaldehydes gave

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• substituents to make little contribution to the HOMO of either 1H or 12 (as shown in calculated molecular orbitals for several examples [14][50][55][59][60]) and so the dependence of these potentials on Y is likely to be due to a combination of inductive effects and perhaps steric effects on the molecular

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

• Alessio Regni,
• Francesca Bartoccini and
• Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

• the importance of steric effects [99]. Indeed, while the addition of the nucleophilic α-amino radical to the α-styrenyl position affords the 6-membered ring (kinetic product via intramolecular 6-exo-trig ring closure) [100] the resulting radical is unstabilized, the 7-membered ring (obtained via

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• possessing representative functional groups was employed subsequently to evaluate the reaction scope and limitations (Scheme 3). Under the optimized conditions, alkenes 2b–e with varying steric effects underwent smooth reaction, yielding the corresponding products 3ab–ae in moderate to good yields (56–68

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38