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Search for "atropisomerism" in Full Text gives 12 result(s) in Beilstein Journal of Organic Chemistry.
Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond
Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253
- the glycopeptide antibiotic family [62][63]. Their aromatic rings undergo oxidative coupling to form biaryl moieties that restrict atropisomerism; the resulting rigid structure is key to their high affinity binding to peptidoglycan intermediates [64][65]. Glycopeptide antibiotics include vancomycin
C–C Coupling in sterically demanding porphyrin environments
Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234
- [72]. Many more examples of atropisomeric enrichment methods can be found in a 2024 review on atropisomerism by Maguire et al. [73] and could be further explored to isolate the αβαβ-atropisomer of porphyrin 11. X-ray crystal structure analysis of compound 37 Interestingly the anthracenyl arm-extension
Computation-guided scaffold exploration of 2E,6E-1,10-trans/cis-eunicellanes
Beilstein J. Org. Chem. 2024, 20, 1320–1326, doi:10.3762/bjoc.20.115
- intrinsic properties, which result in protonation-initiated cyclization, Cope rearrangement, and atropisomerism. Finally, we exploited the reactivity of the trans-eunicellane skeleton to generate a series of 6/6/6 gersemiane-type diterpenes via electrophilic cyclization. Keywords: atropisomer; Cope
- ]. In regard to the atropisomerism of 10a/10b, the two atropisomers are approximately equivalent in energy (0.5 kcal mol−1 difference) and require at least 17.4 kcal mol−1 to undergo conversion (Figure 3C). Interestingly, rotation in different directions requires barriers that differ by 2 kcal mol−1
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- that for 58 (ΔG‡298 K = 23.3 kcal mol−1), indicating that the cylohexa-2,5-diene-1,4-diylidene moiety is more flexible and its distortion by out-of-plane bending is energetically less favored compared to the DCV moiety. Guldi et al. reported that the atropisomerism in the TCBD structure was observed
A Streptomyces P450 enzyme dimerizes isoflavones from plants
Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113
- and 2 with respect to atropisomerism was assessed by chiral HPLC analysis and the comparison of experimental and calculated ECD spectra. While 1 showed a ≈3:1 atropisomer ratio, with the M-atropisomer being the major form, 2 did not exhibit a Cotton effect in the ECD measurement, suggesting that it is
Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds
Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185
- of a wide range of axially chiral biaryls, heterobiaryls, vinylarenes, N-arylamines, spiranes, and allenes with high efficiency and excellent stereoselectivity. Keywords: allenes; atropisomerism; axial chirality; chiral phosphoric acid; heterobiaryls; spiranes; Introduction Axial chirality is one
- of the most important properties of nature, resulting from the nonplanar arrangement of four groups in pairs about a chirality axis. These include atropisomerism [1], chiral allenes, spiranes, spiroindanes, and so on [2][3]. Recently, there emerged an enormous demand for enantiopure compounds, not
- generates the chiral environment and played a crucial role in favoring of atropisomerism. A series of axially chiral biaryl-2-amines with 1,1-disubstituted alkenes 17 was efficiently synthesized in moderate to excellent yields (42–96%) with excellent enantioselectivities (up to >99% ee). 2. Enantioselective
Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners
Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186
- connected asymmetric bowls, as well as atropisomerism, was constructed by Hirao and his two group members, namely Amaya and Kobayashi, starting from the same bromo derivative 82. First it was converted into ethynylsumanene 91 using a Sonogashira-coupling which on subsequent desilylation and Glaser-coupling
Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica
Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293
- with pigmentosin A, a 3,4-dihydro-α-naphthopyrone dimer with a 7,7′-dimethoxy pattern, by comparing its spectroscopic data with the published data for pigmentosin A [12]. Nevertheless, the chirality of the stereogenic centers C-3/C-3′ as well as the atropisomerism at the 6,6′ axis of pigmentosin A (1
- due to atropisomerism (Figure 2), although the TDDFT-ECD curve of (3S,3′S,6R)-1 showed a further small positive Cotton effect around 228 nm. Nevertheless, due to the high similarity of both curves, we believe that the calculated ECD data could not distinguish between (3R,3′R,6R)-1 and (3S,3′S,6R)-1
- . Thus, the atropisomerism at the 6-6′ axis of pigmentosin A (1) was determined to be aR, while the absolute configuration of the stereogenic centers C-3/C-3′ remains unsolved. Compound 2 was obtained as pale green powder. The molecular formula of 2 was determined as C32H30O11 based on HRMS data. The 13C
Catalytic asymmetric oxo-Diels–Alder reactions with chiral atropisomeric biphenyl diols
Beilstein J. Org. Chem. 2019, 15, 955–962, doi:10.3762/bjoc.15.92
- work by Goldfuss and his co-worker on an atropisomeric biphenyl compound showed that atropisomerism can be induced and stabilized with hydrogen bonding from fenchyl alcoholic units [36]. Regarding to atropisomeric properties of biphenyl compounds, our group have previously reported the formation of
Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine
Beilstein J. Org. Chem. 2018, 14, 2384–2393, doi:10.3762/bjoc.14.214
- selectivity using a differently ortho-substituted phenylbornic acid was observed. Keywords: arylpyridines; atropisomerism; cross-coupling; palladium; Suzuki–Miyaura reaction; Introduction Axially chiral biaryls not only subsist in many classes of natural and bioactive compounds [1][2] but also are an
- phenomenon of atropisomerism occurring in ortho-substituted di-, tri- and pentaarylpyridine derivatives [35][36][37][38]. The presence of this phenomenon was found in several compounds and also in byproducts formed during the synthesis of analogs of amphetamine prepared by the Leuckart method. The treatment
Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester
Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67
- detected. We have previously observed that nitrile oxide cycloadditions to this hydantoin and related compounds can show facial selectivity based on atropisomerism around the N-aryl bond [38][44]. With benzonitrile oxide the facial selectivity was 30:1 favouring addition anti to the tert-butyl group
Directed aromatic functionalization in natural-product synthesis: Fredericamycin A, nothapodytine B, and topopyrones B and D
Beilstein J. Org. Chem. 2011, 7, 1475–1485, doi:10.3762/bjoc.7.171
- atropdiastereomers. Furthermore, atropisomerism vanishes upon release of the TIPS unit (see below). An inspection of molecular models readily provides a qualitative illustration of this effect, in that the bulky TIPS group hampers rotation about the σ-bond connecting the benzylic carbon to the aryl segment (cf
- , desilylation of 69 (TBAF) furnished an alcohol that, contrary to the parent 69 or other TIPS-protected synthetic intermediates, exhibited no atropisomerism (single compound by 1H and 13C NMR). Oxidation (IBX) and treatment of the emerging ketone 74 with 48% aqueous HBr in AcOH under reflux afforded synthetic
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