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Search for "diastereoselectivity" in Full Text gives 395 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Highly electrophilic, gem- and spiro-activated trichloromethylnitrocyclopropanes: synthesis and structure
Beilstein J. Org. Chem. 2026, 22, 123–130, doi:10.3762/bjoc.22.5
- . Conditions for obtaining the target cyclopropanes were optimized. The process is characterized by high diastereoselectivity and allows obtaining cyclopropanes with trans-configuration of -NO2 and -CCl3 groups. Monocyclic (based on malonic acid dinitrile, methyl cyanoacetate, ethyl cyanoacetate
Total synthesis of natural products based on hydrogenation of aromatic rings
Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4
- diastereoselective hydrogenation of symmetrical 2,5-DKP (2,5-dipiperazinone) 67 using a rhodium complex (Scheme 8) [63]. The saturated pentacyclic compound 68 was obtained in high yield and excellent diastereoselectivity. The hydrogen atoms in the final product were all arranged in cis configuration. Key features of
Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones
Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209
- three nucleophilic centers in 1,3-diaminopropan-2-ol (3), and because there is a need to increase diastereoselectivity of the cyclization process. Table 1 presents the optimization steps for the reaction conditions at various solvents and temperature. The reaction course was monitored by TLC and 19F NMR
- intermediate B, which becomes softer for attack by the amino group. It is worth noting that the diastereoselectivity of octahydropyrido[1,2-a]pyrimidinones formation 4a–c in the reactions with alkyl methyl ketones 2a–c is also affected by the length of the alkyl chain, with the number of diastereomers
- [24], which showed an increase in the diastereoselectivity in synthesis of octahydropyrido[1,2-a]pyrimidinones in the three-component reaction of ethyl trifluoroacetoacetate and 1,3-diaminopropane with methyl ketones with an increase in the volume of substituent in the ketone component. Unlike the
Chemoenzymatic synthesis of the cardenolide rhodexin A and its aglycone sarmentogenin
Beilstein J. Org. Chem. 2025, 21, 2637–2644, doi:10.3762/bjoc.21.204
- )3 could reverse the diastereomeric ratio of the C14-hydroxylated products to dr = 1.5–1.7:1 and increased the yield to 48–58% as well. Nevertheless, the unsatisfactory diastereoselectivity urged us to explore a late-stage Mukaiyama hydration. To this end, we next performed the thermodynamic C11
- with high diastereoselectivity (dr = 14β/14α = 6.7:1), and the minor component 14-epi-sarmentogenin could be readily separated. Notably, our work represents the first protecting-group-free synthesis [34][35] of sarmentogenin in just 7 steps from 17-deoxycortisone. With the aglycone sarmentogenin (2) in
Recent advances in total synthesis of illisimonin A
Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199
- , illisimonin A was obtained only as a minor product. When O2 was replaced with the nitroaromatic compound 66 [38], the diastereoselectivity was reversed, thereby providing illisimonin A in 57% yield as a single diastereomer. The authors proposed that a hydrogen bond between the nitro group of 66 and the C8
Synthesis of the tetracyclic skeleton of Aspidosperma alkaloids via PET-initiated cationic radical-derived interrupted [2 + 2]/retro-Mannich reaction
Beilstein J. Org. Chem. 2025, 21, 2470–2478, doi:10.3762/bjoc.21.189
- , which has a stereogenic centre at C10, photocyclization afforded 10g in moderate yield and with excellent diastereoselectivity (76% yield, dr >20:1). This indicates that the reaction is controlled by the substrate conformation. To investigate the effects of the spirocyclic ring size on the
The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions
Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184
- against other solvents. Keywords: cycloaddition; fused isoxazolidines; renewable solvent; reusable solvent; trans-diastereoselectivity; Introduction It is an established fact that a significant number of conventional organic solvents, which are widely utilized in both industrial and academic contexts
- -H6a and cis-H6a) is shown in Figure 10 for the compound 3a. Conversely, when these two reagents were heated in toluene, the ratio of cis/trans diastereoisomers was observed to be 1:1 [107], indicating that a remarkable diastereoselectivity can be achieved when methyl laurate is used as a solvent. The
- ) between the phenyl rings substituted on the nitrogen atoms of both maleimide and nitrone [109]. The most significant evidence confirming the interactions that determine the diastereoselectivity observed here is that the cis diastereomer is the major addition product in the dipolar cycloaddition reaction
Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177
- moderate diastereoselectivity; this was followed by Mn(III)-catalyzed metal-hydride hydrogen atom (MHAT) transfer to reduce the endocyclic olefin, forming 41 as a single diastereomer. Subsequent transformations – including a Wittig reaction, demethylation, and oxidation of the resulting phenol to a p
Halogenated butyrolactones from the biomass-derived synthon levoglucosenone
Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175
- cascade to give enone 21 in 42% yield. Baeyer–Villiger oxidation of this highly activated alkene promoted an epoxidation/Baeyer–Villiger oxidation cascade to yield lactone 22 in 67% yield (dr 2:1). The low diastereoselectivity suggested that the epoxidation happened subsequent to the ring contraction, as
Enantioselective radical chemistry: a bright future ahead
Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174
- tolerated a range of substituents on the olefin, giving the products with high enantioselectivity. Reactions of chiral β-methyl-substituted aldehydes 11 and 12 with indene (13) yielded tricyclic products with good diastereoselectivity and particularly high optical purity (99% ee). Organo-SOMO catalysis was
- aldolase, a photoredox catalyst, and an oxidizing agent. With this catalytic system, they were able to accomplish the C–H functionalization of glycine and α-branched amino acids, obtaining α-tri- and tetrasubstituted amino acids with moderate to good yields, good diastereoselectivity, and high
Pathway economy in cyclization of 1,n-enynes
Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173
- trapped intermediate 152, affording alkylidenecyclopentenes 153 with high diastereoselectivity (Scheme 31, path b). By clarifying E/Z-configuration-dependent cyclization mechanisms, this work introduced the gold(I)-catalyzed 5-exo-dig cyclization of 1,3-dien-5-ynes, gaining insights into regioselective
C2 to C6 biobased carbonyl platforms for fine chemistry
Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165
The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products
Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164
- 41 afforded the 1,3-cyclopentanedione derivative 42. Next, the baker′s yeast-catalyzed desymmetric enantioselective reduction of 42 gave the α-hydroxyketone 43 in satisfactory yield and excellent stereoselectivity and diastereoselectivity on a decagram scale [33][34]. Functional group modifications
- hydroxyketone 104 in excellent diastereoselectivity and enantioselectivity [9][11]. Ozonolysis of the double bond in 104 followed by Purdie methylation with Ag2O/MeI, base-mediated vinyl triflation, and Pd-catalyzed Suzuki–Miyaura cross coupling with pinacol boronate 105 delivered diene 106. Next, The Et2AlCl
- efficiency was significantly improved. Despite remarkable progress has been made, there is still a long way to go before the strategy achieves maturity for applications in natural products. Specifically, challenges remain in improving the enantioselectivity and diastereoselectivity of the desymmetric
Bioinspired total syntheses of natural products: a personal adventure
Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160
- approach. This key reaction mimics the plausible biosynthetic pathway and demonstrates great efficiency and sole diastereoselectivity, showcasing the plausibility of the biosynthetic proposal. Further redox manipulations of the last olefin and deprotection ultimately provided chabranol. To clearly confirm
- transformation was successfully achieved by using PhI(OAc)2 as oxidant, providing 7-O-demethylmonocerin, containing the cis-substituted THF ring with sole diastereoselectivity. Site-selective mono-methylation gave rise to monocerin. The bioinspired approach successfully found applications in the total synthesis
- gymnothespirolignan A in excellent yield and good diastereoselectivity [38] (Scheme 6c). The minor epimer is gymnothespirolignan C, another natural product of this family. This cascade reaction supports the proposed biogenetic pathway of the newly isolated novel siprocyclic gymnothelignans. The bioinspired double
Understanding the origin of stereoselectivity in the photochemical denitrogenation of 2,3-diazabicyclo[2.2.1]heptene and its derivatives with non-adiabatic molecular dynamics
Beilstein J. Org. Chem. 2025, 21, 2007–2020, doi:10.3762/bjoc.21.156
- bicyclo[1.1.0]butane (a) and bicyclo[2.1.0]pentane (b). Molecules with biological activity are synthesized from bicyclo[1.1.0]butane (c) and bicyclo[2.1.0]pentane (d). Diastereoselectivity in the direct photolysis of 2,3-diazabicyclo[2.2.1]hept-2-enes. Mechanism for the photodenitrogenation of DBH
Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization
Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152
- a single diastereomer (Table 1, entry 4). To explain this diastereoselectivity, we hypothesize that the C–O bond, which occupies an axial position in the proposed transition state TS-1, could avert an additional hyperconjugative interaction (σ*C-O/π) that renders the reacting C=C bond electron
- connection of C8 and C12 in compound 21 could be realized through a photoredox-catalyzed radical cyclization of unactivated alkene-substituted β-ketoester 27. This reaction was expected to involve a 5-exo-trig radical cyclization via transition state TS-3 [38], in which the diastereoselectivity could be
Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151
- hydroxy group, affording aldehyde 238 in 78% yield with >10:1 dr. The high diastereoselectivity observed in the oxidation of the 1,3-diol indicated that the complex structure of the substrate could provide an environment of desymmetrization. The stereospecific cyclization of 238 was performed with
- , compound 266 was prepared in a seven-step sequence. Then, the cascade cyclization was accomplished by treatment with NaOMe in MeOH, followed by H2O, affording compound 267 in excellent yield and diastereoselectivity. A subsequent three-step sequence gave diol 268. Under DDQ and AcOH conditions, the
- diastereoselectivity. Compound 288 was then treated with Co(acac)2, 1,1,3,3-tetramethyldisiloxane (TMDSO), and O2 in degassed iPrOH, undergoing a hydrogen-atom-transfer (HAT)-initiated redox radical cascade to give pentacyclic alcohol 289, which was converted to C18/19 diol 290 in two steps. To differentiate the two
Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules
Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145
- diastereoselectivity. Previously, they have been challenging to access in an asymmetric one-step reaction. A range of paracyclophanes with diverse substitutions, including aryl, heteroaryl, alkynyl and bromo substitutions, along with a varying length of the ansa chain, were found to be amenable to this method
- with poor diastereoselectivity while maintaining high enantioselectivity for both diastereomers (see 76d–g). Furthermore, the authors have investigated the asymmetric condensation using other seven-membered cyclic ketones (see 77a) as well as the coupling with alkylhydroxylamine (see 77b
Structural analysis of stereoselective galactose pyruvylation toward the synthesis of bacterial capsular polysaccharides
Beilstein J. Org. Chem. 2025, 21, 1671–1677, doi:10.3762/bjoc.21.131
- , pyruvate ketals are attached to the O4 and O6 positions of galactose, incorporating a negatively charged carboxyl group. The diastereoselectivity and negative charge of pyruvate ketals have a key role in their biological interaction, such as influencing immunological specificity and patterns of
- was significantly faster, and the starting material was completely consumed within 2 h, followed by deacetylation to yield the desired product 6 in 51% (Table 1, entry 3). The use of this more reactive reagent maintained high R-diastereoselectivity. It is hypothesized that this reaction will yield a
Catalytic asymmetric reactions of isocyanides for constructing non-central chirality
Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129
- ). However, the diastereoselectivity is modest (1.7:1), likely resulting from insufficient chiral induction during the indolinone-forming step. Moving forward, this strategy was applied in the construction of axial chirality by the same group. In 2021, they reported a Pd(OAc)2/L2-catalyzed imidoylative
3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles
Beilstein J. Org. Chem. 2025, 21, 1595–1602, doi:10.3762/bjoc.21.123
- -catalyzed reaction proceeds with low diastereoselectivity. The significant difference in selectivity can be explained by the fact that, in contrast to the Ni(II)-catalyzed reaction depicted in Scheme 3, the copper(I) catalysis involves the coordination by the metal of both reaction partners, and the
Heterologous biosynthesis of cotylenol and concise synthesis of fusicoccane diterpenoids
Beilstein J. Org. Chem. 2025, 21, 1489–1495, doi:10.3762/bjoc.21.111
- conditions, compound 15 and its diastereomer were obtained in a total yield of 90% at a ratio of 1:0.7. To improve the diastereoselectivity, we examined other reduction conditions and found that ʟ-Selectride afforded compound 15 in 90% yield with a dr of 9:1. Upon desilylation with TBAF, compound 15 was
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- diastereomeric ratios favouring the trans-isomer, however, a reversed diastereoselectivity was observed for ortho-substituted aryls due to steric factors. The investigation of the substrate scope revealed that while the reaction shuts down in the absence of the trifluoromethyl group in the ketone component, it
- amidine base catalysis (Scheme 25b) [69]. Although this methodology employs equimolar catalyst loadings, the products 100 are obtained with complete diastereoselectivity and mostly in moderate to good yields. As for the mechanism, it is assumed to be analogous to the NHC-variant. Four years later, Somappa
- halogens, nitriles, alkenes and heteroaryls. On the other hand, this methodology suffers from relatively low diastereoselectivity as the dr lies between 1:1 and 2:1. DFT calculations suggested the reaction proceeds through nitrogen elimination, oxonium ylide 119 formation, homolytic cleavage and radical
Synthetic approach to borrelidin fragments: focus on key intermediates
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- functionality of 87 was reduced to the corresponding primary alcohol with DIBAL-H and converted to the iodide derivative using Ph3P/I2/imidazole reagents. The resulting iodide was treated with lithiated (R,R)-91 to afford compound 86 in a 76% yield with excellent diastereoselectivity (>99:1 dr). Finally
- demonstrated when compound 100 was treated with MeMgBr/CuBr and either 94 or ent-94, affording 101a and 101b, respectively, with high yield and exclusive diastereoselectivity. Compound 101a, featuring the relevant stereochemistry of borrelidin at the C4, C6, C8, and C10, underwent Baeyer–Villiger oxidation
- hydrogenation of 104, employing (R)-[(RuCl(Tol-BINAP))2(μ-Cl)3[NH2Me2], yielded the product in 90% yield with nearly complete diastereoselectivity (de >99%). Finally, the secondary alcohol was protected as a TBS ether, and the ester group was hydrolyzed to deliver Ōmura’s C1–C11 fragment 61 in 85% yield. The
A versatile route towards 6-arylpipecolic acids
Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88
- to investigate how the configuration of the stereocenter in C2 position influences diastereoselectivity. In the first approach, NaBH3CN was used under acidic conditions to reduce the acyliminium intermediate formed from the N-acyl enamine upon protonation at C5, while in the second approach
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