A three-component, Zn(OTf)₂-mediated entry into trisubstituted 2-aminoimidazoles

• Alexei Lukin,
• Anna Bakholdina,
• Anna Kryukova,
• Alexander Sapegin and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2019, 15, 1061–1064, doi:10.3762/bjoc.15.103

• propargylureas (leading to 2-imidazolones) and extend the range of Lewis acid-catalyzed azole syntheses based on N-carbonyl propargylamines. Keywords: alkyne hydroamination; cyclocondensation; Lewis acid catalysis; multicomponent reactions; propargylurea; Introduction The pioneering publications of Beller and

• the mechanistic prospective, the reaction probably proceeds via Zn(OTf)2-catalyzed alkyne hydroamination followed by cyclodehydration as depicted in Figure 3, in full analogy with the previously proposed mechanism [2][3]. Conclusion In summary, we have successfully employed propargylureas in the

Direct access to pyrido/pyrrolo[2,1-b]quinazolin-9(1H)-ones through silver-mediated intramolecular alkyne hydroamination reactions

• Hengshuai Wang,
• Shengchao Jiao,
• Kerong Chen,
• Xu Zhang,
• Linxiang Zhao,
• Dan Liu,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 416–424, doi:10.3762/bjoc.11.47

• Road, Shengyang 110016, P. R. China 10.3762/bjoc.11.47 Abstract We report a synthetic methodology for the construction of the fused heterocyclic compounds pyrido[2,1-b]quinazolin-9(1H)-ones and pyrrolo[2,1-b]quinazolin-9(1H)-ones through an AgOTf-catalyzed intramolecular alkyne hydroamination reaction

• . The methodology is applicable to a wide scope of substrates and produces a series of fused quinazolinone heterocycles in good to excellent yields. Keywords: heterocyclic molecules; intramolecular alkyne hydroamination; silver; Introduction Quinazolinone is a core skeleton for naturally existing

• through an AgOTf-catalyzed intramolecular alkyne hydroamination cyclization reaction. The methodology is applicable to a wide scope of substrates and generates a series of fused quinazolinone heterocycles in good to excellent yields. It lends itself an alternative method to the construction of innovative

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• coupling of aryl chlorides. This was followed by an intramolecular alkyne–hydroamination (addition of an N–H bond across a carbon–carbon multiple bond) leading to the corresponding indole derivatives 52. The amination/alkyne–hydroamination sequence requires the addition of 1.5 equiv of t-BuOK to reach

Combination of gold catalysis and Selectfluor for the synthesis of fluorinated nitrogen heterocycles

• Antoine Simonneau,
• Pierre Garcia,
• Jean-Philippe Goddard,
• Virginie Mouriès-Mansuy,
• Max Malacria and
• Louis Fensterbank

Beilstein J. Org. Chem. 2011, 7, 1379–1386, doi:10.3762/bjoc.7.162

• explained either by direct fluorination of the enamine resulting from the gold-promoted alkyne hydroamination or by oxidation of the intermediate vinyl gold(I) complex by Selectfluor into a gold(III) fluoride species followed by a reductive elimination. Moreover, the formation of C(sp2)–F bonds, either by

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• gold pre-catalyst 125 featuring a P,N-ligand that has significantly extended the substrate scope and synthetic utility of alkyne hydroamination [60]. The hydroamination of unsymmetrical internal aryl acetylenes 126 with dialkylamines 127 has been achieved with synthetically useful regioselectivities

• malononitriles 375 and N-Boc-protected imines 374 (Scheme 60) [176]. In the alkyne hydroamination (which is based on a bifunctional organocatalytic Mannich-type reaction, subsequent gold-catalyzed alkyne hydroamination and isomerization) thiourea-based hydrogen bonding organocatalyst 373 and PPh3AuNTf2 proved to