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Search for "cycloisomerization reactions" in Full Text gives 12 result(s) in Beilstein Journal of Organic Chemistry.
One-pot Ugi-azide and Heck reactions for the synthesis of heterocyclic systems containing tetrazole and 1,2,3,4-tetrahydroisoquinoline
Beilstein J. Org. Chem. 2024, 20, 912–920, doi:10.3762/bjoc.20.81
- oxidative cycloisomerization reactions for the synthesis of 2-tetrazolyl-substituted 3-acylpyrroles (Scheme 2C) [42]. The Ding group also reported sequential Ugi-azide/Staudinger/aza-Wittig/addition/Ag-catalyzed cyclization reactions for obtaining 12-tetrazolyl-substituted (E)-5H-quinazolino[3,2-a
Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives
Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163
- release of a nitrogen molecule to form the desired product 46. In 2018, Ding and co-workers reported the synthesis of 2-tetrazolyl-substituted 3-acylpyrroles 53 via sequential Ugi-azide/Ag-catalyzed oxidative cycloisomerization reactions in good yield (Scheme 20) [64]. Firstly, The Ugi-azide reaction
Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis
Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239
- complexes 1a–d were evaluated as homogeneous catalysts in two tandem addition/cycloisomerization reactions using alkynes 2 and 3. 2-Alkynylbenzaldehyde 2 [58][59] was chosen as the first model substrate for a cyclization reaction in the presence of methanol as a second nucleophile. This tandem addition
- tandem addition/cycloisomerization reactions on model alkynes to give the expected cyclization products in excellent yields, also by using 0.5 mol % catalytic loading, with efficiencies similar to those reported in the literature [60][61][62][63] with inorganic silver salts and complexes employed at
- candidates for directional metal coordination. Herein, a new syn-atropisomer of 9,10-DPA ortho-substituted by two thioethers is exploited as a ligand for silver(I) salts. The impact of this bis-thioether ligand on silver(I) homogeneous catalysis is evaluated in two tandem addition/cycloisomerization
Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization
Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110
- an atom- [5], step- [6], and redox-economical [7] class of reactions that are able to stitch together cyclic molecules quickly and efficiently. The very first enyne cycloisomerization reactions were reported by the Trost group while they were synthesizing substrates intended for thermal Alder–ene
- molecular architectures hold a particular interest to the chemical community, especially in the fields of natural product synthesis and drug design, researchers have made a significant effort to discover asymmetric variations of enyne cycloisomerization reactions [11][12]. Researchers have used a variety of
- simple 1,6-enynes displayed a broader scope than Mikami’s palladium system, although none of the examples contained a quaternary stereocenter [25]. Asymmetric enyne cycloisomerization reactions can be extended beyond the construction of 1,4-dienes, depending on the transition metal used and the adjacent
Silver and gold-catalyzed multicomponent reactions
Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46
- mechanism. This part of the review is divided in sections related to the nature of the activated functionalities. Reaction involving activation of carbon–carbon multiple bonds. This section primarily discusses cycloisomerization reactions involving the addition of imines to silver-activated carbon–carbon
- -catalyzed MCRs involving imines in cycloisomerization reactions follow the main reaction pathway shown in Scheme 18. Starting from a γ-ketoalkyne [51] encompassed in a (hetero)aromatic framework, a condensation step with a suitable G–NH2 group (amine or hydrazine) provides the imine intermediate, which
Gold(I)-catalyzed 6-endo hydroxycyclization of 7-substituted-1,6-enynes
Beilstein J. Org. Chem. 2013, 9, 2242–2249, doi:10.3762/bjoc.9.263
- ; Introduction The cycloisomerization reactions of enynes catalyzed by gold complexes are a powerful tool for accessing complex products from rather simple starting materials under soft and straightforward conditions [1][2][3][4]. In this context, 1,6-enynes have been extensively studied, mainly by Echavarren
Gold(I)-catalyzed hydroarylation reaction of aryl (3-iodoprop-2-yn-1-yl) ethers: synthesis of 3-iodo-2H-chromene derivatives
Beilstein J. Org. Chem. 2013, 9, 2120–2128, doi:10.3762/bjoc.9.249
- accomplish a reaction manifold earlier recognized in the synthesis of regioisomeric halogenated phenanthrenes, but they are using two different metals [45]. Catalytic cycloisomerization reactions of heteroatom-substituted alkynes that take place without heteroatom migration are known [46][47][48]. On this
Combination of gold catalysis and Selectfluor for the synthesis of fluorinated nitrogen heterocycles
Beilstein J. Org. Chem. 2011, 7, 1379–1386, doi:10.3762/bjoc.7.162
- the elucidation of the mechanism and Selectfluor was suggested to play the double role of promoting the oxidation of gold(I) to a gold(III) active species and also the electrophilic fluorination of the enamine intermediates. Keywords: cycloisomerization reactions; fluorinated pyrrolidines; gold
Asymmetric Au-catalyzed cycloisomerization of 1,6-enynes: An entry to bicyclo[4.1.0]heptene
Beilstein J. Org. Chem. 2011, 7, 1021–1029, doi:10.3762/bjoc.7.116
- gold-catalyzed cycloisomerization reaction of heteroatom tethered 1,6-enynes is described. The cycloisomerization reactions were conducted in the presence of the chiral cationic Au(I) catalyst consisting of (R)-4-MeO-3,5-(t-Bu)2-MeOBIPHEP-(AuCl)2 complex and silver salts (AgOTf or AgNTf2) in toluene
- , was reported in moderate to good yields and in enantiomeric excesses up to 99%. Keywords: asymmetric catalysis; bicycloheptene; cycloisomerization reactions; enynes; gold; Introduction Metal-catalyzed cycloisomerization reactions of 1,n-enynes have emerged as efficient processes that contribute to
- % isolated yield respectively) resulting from 5-exo- and 6-endo cycloisomerization reactions [20][66]. Thus, the gold catalytic system cannot compete with the results obtained for the cyclizations of nitrogen-tethered enynes in the presence of iridium, platinum or rhodium catalysts [41][42][43][44][45]. The
Recent advances in the gold-catalyzed additions to C–C multiple bonds
Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103
- -piperidine derivatives. Some functionalized carbo- and heterocycles 232 were synthesized via gold-catalyzed cycloisomerization reactions of enynes 231 [110]. The PPh3AuCl/AgSbF6 catalytic system promotes a Friedel–Crafts type addition of electron-rich aromatic and heteroaromatic derivatives to the non
- -activated alkene followed by a C–C bond cyclization reaction. The carbon, oxygen and nitrogen tethered 1,6-enynes react smoothly with methoxy substituted benzenes, indoles, pyrroles and furans as nucleophilic partners (Scheme 42). The cycloisomerization reactions of boronated enynes 233 was achieved with
High chemoselectivity in the phenol synthesis
Beilstein J. Org. Chem. 2011, 7, 794–801, doi:10.3762/bjoc.7.90
- much less widespread [2][3][15]. The gold-catalyzed ene–yne cycloisomerization reactions are, mechanistically, very complex reactions [16][17][18], and the furan–yne cycloisomerization is no exception. For the latter reaction arene oxides D [19] and oxepines C [20] could be detected as intermediates
Gold catalysis for organic synthesis
Beilstein J. Org. Chem. 2011, 7, 553–554, doi:10.3762/bjoc.7.63
- , cycloaddition and cycloisomerization reactions, to applications in enantioselective catalysis, oxidative coupling and the total synthesis of natural products, and transformations of alkynes, allenes, alkenes and even C–H bonds. A true treasure chest of reactivity! I am grateful to all of the authors that have
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