Are dispersion corrections accurate outside equilibrium? A case study on benzene

• Tim Gould,
• Erin R. Johnson and
• Sherif Abdulkader Tawfik

Beilstein J. Org. Chem. 2018, 14, 1181–1191, doi:10.3762/bjoc.14.99

• than the pairwise C10 contribution [41] and consequently is negligible for most applications compared to 3-body electronic effects [42][43][44]. Mathematically, the ATM treatment is most applicable when the energy contribution from 3rd and higher order terms converge rapidly as a function of inverse

Synthetic avenues towards a tetrasaccharide related to Streptococcus pneumonia of serotype 6A

• Aritra Chaudhury,
• Mana Mohan Mukherjee and
• Rina Ghosh

Beilstein J. Org. Chem. 2018, 14, 1095–1102, doi:10.3762/bjoc.14.95

• the central gluco-rhamno disaccharide the benzylidene protected glucosyl donor (Figure 2) was selected, because the induction of the 1,2-cis selectivity in benzylidene-protected substrates via torsional/electronic effects have already been recognized [28]. The galactosyl trichloroacetimidate donor 2

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• acetoxylation at the activated benzyl carbon adjacent to an oxygen atom proceeded smoothly as shown by the formation of the pseudo acetal 2g (Table 2, entry 6). Diphenylmethane and its derivatives were very good substrates for our system and were less sensitive to the electronic effects of the aromatic ring

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• modified nucleosides arise from changes in hydrogen bonding motifs, electronic effects, hydrophobic interactions, acid-base properties and chemical reactivity [25][26][27][28][29][30][31][32][33][34][35][36][37]. One such modification is the change in the nature of the glycosidic bond [29][37]. Although

Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

• Lingjun Xu,
• Shuwen Han,
• Linjie Yan,
• Haifeng Wang,
• Haihui Peng and
• Fener Chen

Beilstein J. Org. Chem. 2018, 14, 309–317, doi:10.3762/bjoc.14.19

• chloramphenicol scaffold. Electronic effects were first investigated. Generally, electron deficient catalysts gave better reactivity and enantioselectivity than electron-rich variants (Table 1, entries 1–9). Among them, 7i performed best with 95% yield and 92% ee in 17 h (Table 1, entry 9). The surprising

Quinone-catalyzed oxidative deformylation: synthesis of imines from amino alcohols

• Xinyun Liu,
• Johnny H. Phan,
• Benjamin J. Haugeberg,
• Shrikant S. Londhe and
• Michael D. Clift

Beilstein J. Org. Chem. 2017, 13, 2895–2901, doi:10.3762/bjoc.13.282

• -methylphenylglycinol (1b) and 2-chlorophenylglycinol (1c) delivered the corresponding imines in 68% yield (Table 2, entries 2 and 3). The meta-fluoro derivative provided imine 7d in 60% yield (Table 2, entry 4). Electronic effects were studied by examining a series of para-substituted phenylglycinol derivatives (Table

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• moieties, then a molar optical rotation as large as ca. −80 deg dm−1 M−1 should be expected. By analogy with what observed for polysaccharides [41][42], differences with the observed values might be in principle ascribed to either electronic effects, or conformational rearrangements of the overall

• macrocycle structure. However, the fact that Θ2, Θ3 and Θ4 values are similar indicates that extensive deprotonation of the macrocycle has a minor outcome; therefore, a significant contribution from electronic effects may be ruled out. On the other hand, large conformational rearrangements deriving from

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• electronic effects exerted by different substituents, or liquid or solid character of the starting materials. Interestingly, in most cases a simple manual mechanical agitation of the reaction mixtures in a mortar provided products after only a few minutes of grinding. However, the combination of an electron

Photocatalyzed synthesis of isochromanones and isobenzofuranones under batch and flow conditions

• Manuel Anselmo,
• Lisa Moni,
• Hossny Ismail,
• Davide Comoretto,
• Renata Riva and
• Andrea Basso

Beilstein J. Org. Chem. 2017, 13, 1456–1462, doi:10.3762/bjoc.13.143

• , entry 7). Apparently, the electronic effects of the substituents of the diazonium salt play a major role, especially when considering the reactivity of benzenediazonium tetrafluoroborate 11c which, upon reaction with 2-ethoxycarbonylstyrene (12a), furnished only traces of the products, showing a

Phosphorus pentasulfide mediated conversion of organic thiocyanates to thiols

• Chandra Kant Maurya,
• Avik Mazumder and
• Pradeep Kumar Gupta

Beilstein J. Org. Chem. 2017, 13, 1184–1188, doi:10.3762/bjoc.13.117

• potassium thiocyanate in refluxing propylene glycol [19]. Simple short chain thiocyanates were found to react rapidly to give the corresponding thiols. In comparison to the alkyl substrates, the benzyl derivative reacted sluggishly possibly due to electronic effects which was further evident by the longer

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• predominantly occurred at the position ortho to the aniline group. A mechanism investigation showed that the different regioselectivity was controlled by steric and electronic effects. In 2015, Hong and co-workers developed a C–H hydroxylation protocol for flavones; their work is of importance because the

Selective and eco-friendly procedures for the synthesis of benzimidazole derivatives. The role of the Er(OTf)₃ catalyst in the reaction selectivity

• Natividad Herrera Cano,
• Jorge G. Uranga,
• Mónica Nardi,
• Antonio Procopio,
• Daniel A. Wunderlin and
• Ana N. Santiago

Beilstein J. Org. Chem. 2016, 12, 2410–2419, doi:10.3762/bjoc.12.235

• show that the electronic effects of the substituents present in the aldehydes play a significant role in the reaction pathway. The 1,2-disubstituted benzimidazoles were obtained when electron-rich aldehydes were used, while 2-monosubstituted benzimidazoles were obtained from the reaction with electron

Experimental and theoretical investigations into the stability of cyclic aminals

• Edgar Sawatzky,
• Antonios Drakopoulos,
• Martin Rölz,
• Christoph Sotriffer,
• Bernd Engels and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 2280–2292, doi:10.3762/bjoc.12.221

• investigations into their stability towards hydrolysis depending on the pH value are lacking. Results: A set of cyclic aminals was synthesized and their stability quantified by kinetic measurements. Steric and electronic effects were investigated by choosing appropriate groups. Both molecular mechanics (MM) and

• density functional theory (DFT) based studies were applied to support and explain the results obtained. Rapid decomposition is observed in acidic aqueous media for all cyclic aminals which occurs as a reversible reaction. Electronic effects do not seem relevant with regard to stability, but the magnitude

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• ). Regiocontrol of the nitroso hetero-Diels–Alder reaction As discussed above, the nitroso hetero-Diels–Alder reaction can be highly regioselective due to the influences of diene substituents and electronic effects. However, reports on the specific regiocontrol of the reaction are rare. In general, the

• results from various electronic effects and the stereoselectivity can be influenced by the use of chiral dienes or dienophiles or the application of asymmetric catalysis. These methods, mainly the last one, take place in solution, while the solid-phase approaches described in the literature were not

Flow carbonylation of sterically hindered ortho-substituted iodoarenes

• Carl J. Mallia,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1503–1511, doi:10.3762/bjoc.12.147

• and trifluoromethyl groups may be inferred (Scheme 4, 11, 13). A more pronounced decrease in yield was obtained for substrates 14 and 15 (Scheme 4, 63% and 60%, respectively) probably due to the larger size of these groups and as well as electronic effects (the more electron withdrawing

• substituents or electron-donating groups giving better yields (Scheme 4, compounds 17, 19–21) than the more electron-withdrawing CF3 group (Scheme 4, compound 18). In the case of 22 the attached aromatic ring introduces both the ortho substituted sterics and the electronic effects from the additional aromatic

• of ortho-substituted substrates giving moderate to good yields. Comparison of 22 with 32 also showed that the steric encumbrance on the ortho position has an effect on the yield even when other electronic effects are in place such as those coming from the additional aromatic ring attached. A scale-up

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• -acetyl-2H-chromen-2-ones bearing an electron-withdrawing group gave the products in lower yields and with low ee values. In contrast, good reactivity and high enantioselectivity were observed for those with a electron-donating methoxy group probably due to the electronic effects. The final products

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• that have found that heteroatoms accelerate C–H bond insertion at adjacent carbons. The Lee group performed further studies on the electronic effects of the oxygen on the rate of bond insertion, and concluded that the ability of the oxygen lone pair to align with the σ* orbital of the C–H bond targeted

Enantioselective carbenoid insertion into C(sp³)–H bonds

• J. V. Santiago and
• A. H. L. Machado

Beilstein J. Org. Chem. 2016, 12, 882–902, doi:10.3762/bjoc.12.87

• efforts to better comprehend the scope of this catalytic system, especially on features concerning the BARF salt effect [43][44] and electronic effects on the aromatic rings of the chiral ligands [45]. In 2014, Maguire at al reported the syntheses of N-heterocycles by the enantioselective insertion of

Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• the targeted C–H bond. While secondary and tertiary C(sp3)–H bonds are favored toward the electron-deficient carbenic carbon center in terms of electronic effects, they are unfavored in terms of steric hindrance. The primary C(sp3)–H bonds operate in the opposite way. Further studies in this area will

Diradical reaction mechanisms in [3 + 2]-cycloadditions of hetaryl thioketones with alkyl- or trimethylsilyl-substituted diazomethanes

• Grzegorz Mlostoń,
• Paulina Pipiak and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 716–724, doi:10.3762/bjoc.12.71

• presence of the Me or Me3Si groups in the S-methanide moiety. However, electronic effects resulting from the diradical nature of the intermediate thiocarbonyl ylides, can also play certain role. The same effect was observed in the case of diaryldiazomethanes used in reactions with aryl/hetaryl thioketones

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• towards electronic effects, the copper-mediated cross-coupling reaction is not very sensitive to steric crowding in the neighborhood of the reaction center. Next, we employed heteroaromatic boronic acids, such as furan-2-ylboronic acid (10i; Table 2, entry 8), thiophen-2-ylboronic acid (10j; Table 2

Hydroquinone–pyrrole dyads with varied linkers

• Hao Huang,
• Christoffer Karlsson,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

• of non-conjugated 3a and 3b closely resemble the sum of absorptions from the individual DMB and pyrrole spectra, indicating the absence of substantial electronic effects from the substituent. On the other hand, for the conjugated 3c, 3d and 1, a red shift is observed when compared to the individual

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

• Davide Bello and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

• always be detected (and not removed) from the desired product 2f. We were also interested in exploring the electronic effects of para-substitution of the phenyl group directly attached to the ethynyl moiety on the reaction outcome; thus we selected compounds 1g–j and reacted them under our

Stereochemistry of ring-opening/cross metathesis reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles with allyl alcohol and allyl acetate

• Piotr Wałejko,
• Michał Dąbrowski,
• Lech Szczepaniak,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 1893–1901, doi:10.3762/bjoc.11.204

• , however, some electronic effects in 7-oxanorbornene should be also taken into consideration. Unexpectedly, the Z-selectivity predominated in most reactions catalyzed by [Ru]1 (see Table 1, entries 1–6, 10–15, and Table 2, entries 1–4). A two-fold excess of the Z isomer was observed in both groups of

• strained than D. On the other hand, an interaction of less bulky o-tolyl ligands with the ruthenium core in [Ru]5 causes an opposite selectivity (E preference). One can assume that the observed change in the E/Z selectivity resulted from chelating and electronic effects in postulated intermediates C and D

A comprehensive study of olefin metathesis catalyzed by Ru-based catalysts

• Albert Poater and
• Luigi Cavallo

Beilstein J. Org. Chem. 2015, 11, 1767–1780, doi:10.3762/bjoc.11.192

• , respectively. Steric effects have little influence on the absolute C2H4 binding energy, E of 3rd column in Table 2, since rather similar values are calculated for 2 and 5 (−18.6 and −19.1 kcal/mol, respectively). Differently, electronic effects influence the ability of the Ru atom to capture C2H4, particularly

• differentiation between the power of the three effects, steric, electronic and solvent, has turned out be a hazard to make predictions difficult. However the CF3 groups have become key to explain the electronic effects, as well as the t-Bu for steric effects. Steric effects owing to interaction between bulky NHC