Transition-metal-free [3 + 3] annulation of indol-2-ylmethyl carbanions to nitroarenes. A novel synthesis of indolo[3,2-b]quinolines (quindolines)

• Michał Nowacki and
• Krzysztof Wojciechowski

Beilstein J. Org. Chem. 2018, 14, 194–202, doi:10.3762/bjoc.14.14

• reaction with 2,4-dichloronitrobenzene (2f), where we obtained 3-(indol-2-yl)-2,1-benzisoxazole 10 instead of the expected indoloquinoline. In an analogous reaction with 1-nitronaphthalene (2g) condensed isoxazole derivative 11 was formed (Scheme 3). The formation of 2,1-benzisoxazoles in reactions of

Synthesis of 2,1-benzisoxazole-3(1H)-ones by base-mediated photochemical N–O bond-forming cyclization of 2-azidobenzoic acids

• Daria Yu. Dzhons and
• Andrei V. Budruev

Beilstein J. Org. Chem. 2016, 12, 874–881, doi:10.3762/bjoc.12.86

• -benzisoxazolones; 1,5-electrocyclization; nitrenes; photochemical cyclization; Introduction Substituted 2,1-benzisoxazoles display diverse biological activity [1][2][3][4][5][6] (Figure 1) and are widely used as starting materials for the synthesis of important heterocyclic pharmacophores, such as acridines [7][8

• ], quinolines [9][10][11][12][13] and quinazolines [14][15][16]. Therefore, the search for new methods leading to 2,1-benzisoxazoles is of great interest. For the preparative synthesis of 2,1-benzisoxazoles, in addition to the traditional method based on the reductive heterocyclization of ortho-substituted

• preparation. Thus the search for new methods for the synthesis of substituted 2,1-benzisoxazoles under mild reaction conditions is required. Previously, in the investigation of the photochemical cyclization of 2-azidobenzoic acid (1a) using aqueous organic solvent mixtures (Scheme 1), the formation of the

Synthesis of SF₅-containing benzisoxazoles, quinolines, and quinazolines by the Davis reaction of nitro-(pentafluorosulfanyl)benzenes

• Petr Beier and
• Tereza Pastýříková

Beilstein J. Org. Chem. 2013, 9, 411–416, doi:10.3762/bjoc.9.43

• arylacetonitriles to provide the SF5-containing benzisoxazoles. Good yields were obtained with arylacetonitriles containing the electron-neutral or electron-donor group, while those with the electron-acceptor group were found to be unreactive. Reductions of the benzisoxazoles gave ortho-aminobenzophenones in high

• yields. Their synthetic utility was demonstrated by condensation reactions with carbonyl compounds or amines to provide SF5-containing quinolines and quinazolines, respectively. Keywords: benzisoxazoles; pentafluorosulfanyl group; quinazolines; quinolines; sulfurpentafluorides; Introduction Reactions

• atoms bearing hydrogen and the formation of anionic σH adducts [1][2][3][4][5][6]. One example of such a reaction is the formation of benzisoxazoles (anthraniles) from substituted nitrobenzenes and arylacetonitriles in the presence of hydroxide in alcoholic solvent. This reaction was first reported by

Novel base catalysed rearrangement of sultone oximes to 1,2-benzisoxazole- 3-methane sulfonate derivatives

• Veera Reddy Arava,
• Udaya Bhaskara Rao Siripalli,
• Vaishali Nadkarni and
• Rajendiran Chinnapillai

Beilstein J. Org. Chem. 2007, 3, No. 20, doi:10.1186/1860-5397-3-20

• as shown in Scheme 2. Although the reactions in Scheme 2 were successfully implemented on large scale (~100 kgs), the lachrymatric nature of compound 4 (X = Br) created significant handling problems to the operating personnel. In our efforts to prepare the benzisoxazoles 10 without involving