16017-24-6Relevant academic research and scientific papers
(E)-2-(4-Arylbut-1-en-3-yn-1-yl)chromones as Synthons for the Synthesis of Xanthone-1,2,3-triazole Dyads
Albuquerque, Hélio M. T.,Santos, Clementina M. M.,Cavaleiro, José A. S.,Silva, Artur M. S.
, p. 4732 - 4743 (2015)
Xanthone-1,2,3-triazole dyads have been synthesized by two different approaches, both starting from novel (E)-2-(4-arylbut-1-en-3-yn-1-yl)chromones, prepared through a base-catalyzed aldol reaction of 2-methylchromone and arylpropargyl aldehydes. In the first method, the xanthone moiety is built by Diels-Alder reaction of the referred unsaturated chromones with N-methylmaleimide under microwave irradiation, followed by oxidation of the obtained adducts with DDQ, whereas the 1,2,3-triazole ring results from the cycloaddition reaction of the acetylene moiety with sodium azide. The second strategy first involves the cycloaddition reaction with sodium azide to provide the 1,2,3-triazole ring, followed by methylation of the triazole NH group prior to Diels-Alder reaction with N-methylmaleimide. The last step in this synthesis of novel xanthone-1,2,3-triazole dyads entails oxidation of the cycloadducts with DDQ.
Copper-Free Solid-Phase Synthesis of Triazolo[1,5-a][1,4]diazepin-6-ones
Kriegelsteinová, Patricia,Lemrová, Barbora,Ru?ilová, Veronika,Soural, Miroslav
, p. 1112 - 1119 (2021)
Synthesis of triazolo[1,5-a][1,4]diazepin-6-ones on solid support is reported in this article. Amino acids immobilized on Wang resin were nosylated and alkylated with propargyl alcohol, but-2-yn-1-ol or different 3-phenylprop-2-yn-1-ols using Mitsunobu alkylation conditions. After denosylation, acylation with Fmoc-azidoalanine yielded linear precursors that were thermally cyclized on resin to give immobilized triazolodiazepinones. After cleavage from the polymer support, the target compounds were obtained in high crude purities and good overall yields. Furthermore, the synthetic approach was applied to convenient solid-phase synthesis of oligopeptide containing the triazolodiazepinone moiety as the peptidomimetic heterocyclic constraint. (Figure presented.).
Construction of All-Carbon Quaternary Stereocenters by Palladium-Catalyzed Decarboxylative Propargylation
O'Broin, Calvin Q.,Guiry, Patrick J.
, p. 5402 - 5406 (2019)
A method for the construction of chiral quaternary stereocenters has been accomplished via decarboxylative palladium-catalyzed propargylic alkylation. Both pressurized sealed tubes and microwave irradiation have proven successful for this transformation, yet despite these forcing conditions a range of α-aryl,α-propargyl, and α-alkyl,α-propargyl containing all-carbon quaternary products have been synthesized in good yields and high enantioselectivities (up to 92:8 er). While palladium-catalyzed decarboxylative allylic alkylation has been well studied, this work represents the furthest advancement for the propargylic variant to date.
Rearrangement of Threonine- And Serine-Based N-(3-Phenylprop-2-yn-1-yl) Sulfonamides Yields Chiral Pyrrolidin-3-ones
Králová, Petra,Maloň, Michal,Pospí?il, Ji?í,Soural, Miroslav
, (2019)
N-(3-Phenylprop-2-yn-1-yl)-sulfonamides derived from serine and threonine were synthesized using solid-phase synthesis and subjected to reaction with trimethylsilyl trifluoromethanesulfonate (TMSOTf). In contrast to the previously reported formation of 1,
Efficient Synthesis of Polysubstituted Furans through a Base-Promoted Oxacyclization of (Z)-2-En-4-yn-1-ols
Hrizi, Asma,Thiery, Emilie,Romdhani-Younes, Moufida,Jacquemin, Johan,Thibonnet, Jér?me
supporting information, p. 3798 - 3806 (2021/06/14)
An efficient base catalyzed oxacyclization of Z-enynols has been developed under transition metal-free reaction conditions, thus resulting in a variety of new di-, tri-, and tetra-substituted furans. This approach allowed us to obtain 32 new compounds. Furthermore, DFT calculations were realized to depict a relationship between the natural population analysis and experimental results with alkyl or aryl groups for the synthesis of 2-benzylfuran. A one-pot Sonogashira/oxacyclization approach offers a flexible, robust and efficient alternative to base catalyzed cyclization is also carried out.
Synthesis of Azepino[1,2-a]indole-10-amines via [6+1] Annulation of Ynenitriles with Reformatsky Reagent
Iioka, Ryoya,Yorozu, Kohei,Sakai, Yoko,Kawai, Rika,Hatae, Noriyuki,Takashima, Katsuki,Tanabe, Genzoh,Wasada, Hiroaki,Yoshimatsu, Mitsuhiro
supporting information, p. 1553 - 1558 (2021/02/26)
Lewis acid-catalyzed [6+1] annulation reactions of 2-cyano-1-propargyl- and 2-alkynyl-1-cyanomethyl-indoles with Reformatsky reagent are described. 8-Aryl, 8-alkyl-, 8-hetaryl-, 9-aryl, and 9-alkyl-azepino[1,2-a]indole amines were obtained through a 7-endo-mode cyclization of the β-aminoacrylate intermediates. The antiproliferative activity of the azepino[1,2-a]indoles analogs against the HCT-116 cells were also examined.
Unified Approach to Furan Natural Products via Phosphine-Palladium Catalysis
Chen, Violet Yijang,Kwon, Ohyun
supporting information, p. 8874 - 8881 (2021/03/17)
Polyalkyl furans are widespread in nature, often performing important biological roles. Despite a plethora of methods for the synthesis of tetrasubstituted furans, the construction of tetraalkyl furans remains non-trivial. The prevalence of alkyl groups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkyl furans, calls for a general synthetic protocol for polyalkyl furans. This paper describes a Michael–Heck approach, using sequential phosphine-palladium catalysis, for the preparation of various polyalkyl furans from readily available precursors. The versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes, namely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran; the marine natural products plakorsins A, B, and D and plakorsin D methyl ester; and the furan fatty acids 3D5 and hydromumiamicin.
Intercepting the Banert cascade with nucleophilic fluorine: Direct access to α-fluorinated: N H-1,2,3-triazoles
Alexander,Kevorkian,Topczewski
supporting information, p. 5024 - 5027 (2021/05/28)
The treatment of propargylic azides with silver(i) fluoride in acetonitrile was found to yield α-fluorinated NH-1,2,3-triazoles via the Banert cascade. The reaction was regioselective and the products result from an initial [3,3] rearrangement. The reacti
Enantioselective Nickel-Catalyzed Alkyne-Azide Cycloaddition by Dynamic Kinetic Resolution
Liu, En-Chih,Topczewski, Joseph J.
supporting information, p. 5308 - 5313 (2021/05/04)
The triazole heterocycle has been widely adopted as an isostere for the amide bond. Many native amides are α-chiral, being derived from amino acids. This makes α-N-chiral triazoles attractive building blocks. This report describes the first enantioselective triazole synthesis that proceeds via nickel-catalyzed alkyne-azide cycloaddition (NiAAC). This dynamic kinetic resolution is enabled by a spontaneous [3,3]-sigmatropic rearrangement of the allylic azide. The 1,4,5-trisubstituted triazole products, derived from internal alkynes, are complementary to those commonly obtained by the related CuAAC reaction. Initial mechanistic experiments indicate that the NiAAC reaction proceeds through a monometallic Ni complex, which is distinct from the CuAAC manifold.
Copper-Catalyzed Cross-Nucleophile Coupling of β-Allenyl Silanes with Tertiary C-H Bonds: A Radical Approach to Branched 1,3-Dienes
Shan, Qi-Chao,Hu, Lu-Min,Qin, Wei,Hu, Xu-Hong
supporting information, p. 6041 - 6045 (2021/08/03)
Described herein is a distinctive approach to branched 1,3-dienes through oxidative coupling of two nucleophilic substrates, β-allenyl silanes, and hydrocarbons appending latent functionality by copper catalysis. Notably, C(sp3)-H dienylation proceeded in a regiospecific manner, even in the presence of competitive C-H bonds that are capable of occurring hydrogen atom transfer process, such as those located at benzylic and other tertiary sites, or adjacent to an oxygen atom. Control experiments support the intermediacy of functionalized alkyl radicals.
