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Search for "trans-diastereoselectivity" in Full Text gives 11 result(s) in Beilstein Journal of Organic Chemistry.
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
- structure, results in elevated cis or trans diastereoselectivity [85][111]. Furthermore, the [3 + 2] cycloaddition reactions of nitrones with electron-poor dipolarophiles, such as N-phenylmaleimide, is controlled by the HOMO FMO of the nitrone. Consequently, it can be deduced that HOMOnitrone–LUMON
- functionality have been observed to exhibit notable trans diastereoselectivity in the context of cycloaddition reactions [130][131][132][133][134][135]. For this purpose, equivalent amounts of nitrone 1a and maleimide 2a were reacted with 5 mol % catalyst (Table 5) under the cycloaddition conditions determined
Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold
Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109
- arylation product 9. The trans-diastereoselectivity in the latter process is reasonably justified by the approach of the arene molecule to carbocation 17 from the sterically less hindered side (Scheme 5). Compounds 9 have a pronounced three-dimensional character which makes this novel chemotype a promising
Regioselectivity of the SEAr-based cyclizations and SEAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles
Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33
- -butyloxycarbonylation and N-alkylation (Scheme 14) [25]. The C5 cyclization regioselectivity and trans-diastereoselectivity were not influenced by the electronic nature of the indole-N-substituent. Conclusion As illustrated by these studies, SEAr-based intramolecular cyclization and annulation reactions of 3,5
α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams
Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58
- -cyclopent-2-enyl or N-cyclohex-2-enyl amides 9o,p (cf. Scheme 3). The 5-exo cyclization step of radicals 21o,p proceeds with good to exclusive trans diastereoselectivity forming the azabicyclo[3.3.0]octyl or azabicyclo[4.3.0]nonyl radicals 22o,p (Scheme 11). The subsequent coupling of 22o,p with TEMPO (3
Green synthesis of new chiral 1-(arylamino)imidazo[2,1-a]isoindole-2,5-diones from the corresponding α-amino acid arylhydrazides in aqueous medium
Beilstein J. Org. Chem. 2018, 14, 2923–2930, doi:10.3762/bjoc.14.271
- observed with a total trans-diastereoselectivity controlled by intramolecular hydrogen bonds. Chemical structures of analogues. NOEs correlation showing the stereochemistry of the compound 5a. X-ray crystal structure of 5f shown at the 30% probability level. Strategy for the formation of 1-(arylamino)-1H
A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline
Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138
- 9), isolation of pure diastereomeric CCR adducts was achieved by total esterification of the carboxylic acid product mixture and chromatographic separation of the respective methyl esters (the 0.8:1 anti/syn-10e mixture stereoconverged to anti-10e' on esterification, vide infra). The trans
- -diastereoselectivity of the CCR is well documented in the literature [33] and is, therefore, unsurprising. However, the stereocontrol achieved in this reaction over 3 stereocenters present in 10l (obtained in 81% yield as a single diastereomer) is certainly quite noteworthy and was confirmed by X-ray analysis (Figure
Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction
Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272
- iminium carbon of intermediate A occurred with trans-diastereoselectivity to the C-2 phenyl group. The formation of the diastereomeric cis-7a,b could not be detected. The chiral HPLC analysis of the products 7a,b also confirmed that the reaction took place diastereoselectively and enantiomers of trans-7a
- ,15aS). The good agreement between the experimental HPLC-ECD and computed ECD spectra of 7a,b not only allowed the configurational assignment of their separated enantiomers but also confirmed independently the trans-diastereoselectivity of the cyclization. The neuroprotective activities of rac-7a,b and
- derivative afforded three condensed O,N-heterocycles containing tetrahydro-1,4-benzoxazepine and tetrahydroquinoline moieties. trans-Diastereoselectivity of the cyclizations was determined by the correlation of 3JH,H coupling constants with the geometry of the computed conformers, while (2R,15aR) absolute
Chiral phosphines in nucleophilic organocatalysis
Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218
- temperature, affording a broad spectrum of densely functionalized tetrahydropyridine derivatives, with exclusive 4,5-trans diastereoselectivity, excellent enantioselectivity, and good to excellent yields. The transformations tolerated a wide range of N-sulfonyl-1-aza-1,3-dienes with different C4-substituents
Palladium-catalysed cyclisation of alkenols: Synthesis of oxaheterocycles as core intermediates of natural compounds
Beilstein J. Org. Chem. 2014, 10, 2077–2086, doi:10.3762/bjoc.10.216
- , terminal olefins 30 and threo-9 underwent chlorocyclisation most probably due to the presence of an excess of chloride anions (Table 1, entries 10 and 11). Interestingly, this chlorocyclisation reaction proceeded with high trans-diastereoselectivity, which is in accordance with Wolfe´s TS model [17][18
- presence of BuLi and LiCl provided selectively 5-exo-trig cyclisation products with excellent 2,3-trans diastereoselectivity. Finally, we have also proposed a synthetic access to the dioxaheptane core of natural C15 acetogenins and dioxaoctane, a substructure of the macrolide-polyether antibiotic
New developments in gold-catalyzed manipulation of inactivated alkenes
Beilstein J. Org. Chem. 2013, 9, 2586–2614, doi:10.3762/bjoc.9.294
- treated with a 1:1 mixture of 20a and AgPF6, imidazolidin-2-ones 40 were obtained in high yields under mild reaction conditions (Scheme 11a) [47]. Analogously, substituted N-allylureas 41 provided 42 with high trans diastereoselectivity (dr = 50:1, Scheme 11b). Surprisingly, inversion of
- , affording 5-, 6-membered lactams and spiro-lactams 61 in excellent yields and high trans diastereoselectivity (Scheme 16). 4.2 The hydroarylation reaction In addition to methylene active compounds, electron-rich benzenes and heteroaromatics can be added to gold activated alkenes under suitable conditions
- cyclopentyl and cyclohexyl derivatives in excellent yields and good trans diastereoselectivity, via exo-trig cyclization (Scheme 20a–c). The proposed mechanism involved activation of the C–C double bond by the carbene-based cationic gold species to form the intermediate 76 which underwent gold-promoted
A divergent asymmetric approach to aza-spiropyran derivative and (1S,8aR)-1-hydroxyindolizidine
Beilstein J. Org. Chem. 2007, 3, No. 41, doi:10.1186/1860-5397-3-41
- to N,O-dibenzyl malimide (4) leads to N,O-acetals 5 in high regioselectivity (Scheme 2), and the subsequent reductive dehydroxylation gives 6 in high trans-diastereoselectivity.[35] On the other hand, treatment of N,O-acteals 5 with an acid furnished enamides E, which can be transformed
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