Synthesis of tetrafluorinated piperidines from nitrones via a visible-light-promoted annelation reaction

• Vyacheslav I. Supranovich,
• Igor A. Dmitriev and
• Alexander D. Dilman

Beilstein J. Org. Chem. 2020, 16, 3104–3108, doi:10.3762/bjoc.16.260

• from nitrones and a fluorinated building block is described. The annelation is based on a sequence of visible-light-promoted redox processes and a substitution reaction, and involves the cleavage of the N–O bond. The construction of tetrafluorinated piperidines from nitrones. The scope of the

The synthesis of the 2,3-difluorobutan-1,4-diol diastereomers

• Robert Szpera,
• Nadia Kovalenko,
• Kalaiselvi Natarajan,
• Nina Paillard and
• Bruno Linclau

Beilstein J. Org. Chem. 2017, 13, 2883–2887, doi:10.3762/bjoc.13.280

• opening; fluorinated building block; vicinal difluoride; Introduction The introduction of fluorine in organic compounds usually results in the modification of a range of chemical, physical and biological properties [1]. Fluorine incorporation is therefore a common strategy to optimise the properties of

Syntheses of fluorooxindole and 2-fluoro-2-arylacetic acid derivatives from diethyl 2-fluoromalonate ester

• Antal Harsanyi,
• Graham Sandford,
• Dmitri S. Yufit and
• Judith A.K. Howard

Beilstein J. Org. Chem. 2014, 10, 1213–1219, doi:10.3762/bjoc.10.119

• chemical shift of the doublet (−194.8 ppm) in the 19F NMR spectrum of fluorooxindoles 8a–e is also observed 10 ppm upfield from the fluorine resonance of the starting esters 6a–e. Conclusion Diethyl 2-fluoromalonate ester can be used as a highly effective fluorinated building block for the synthesis of

Stereoselectively fluorinated N-heterocycles: a brief survey

• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2013, 9, 2696–2708, doi:10.3762/bjoc.9.306

• retention (e.g. 50→51, Scheme 4); in the latter example, note that the ring nitrogen does not directly engage in the anchimeric process [62]. 6.2 The fluorinated building block approach An alternative to the strategy of deoxyfluorination (section 6.1) is to synthesise fluorinated N-heterocycles starting

One-pot cross-enyne metathesis (CEYM)–Diels–Alder reaction of gem-difluoropropargylic alkynes

• Santos Fustero,
• Paula Bello,
• Javier Miró,
• María Sánchez-Roselló,
• Günter Haufe and
• Carlos del Pozo

Beilstein J. Org. Chem. 2013, 9, 2688–2695, doi:10.3762/bjoc.9.305

• starting materials. In this context, the recent introduction of difluoropropargyl bromide as fluorinated building block gave access to a wide variety of gem-difluoro-containing alkyne derivatives [21][22]. Recently, we have employed these fluorinated triple bond scaffolds in several types of cyclization

Synthesis and crystallographic analysis of meso-2,3-difluoro-1,4-butanediol and meso-1,4-dibenzyloxy-2,3-difluorobutane

• Bruno Linclau,
• Leo Leung,
• Jean Nonnenmacher and
• Graham Tizzard

Beilstein J. Org. Chem. 2010, 6, No. 62, doi:10.3762/bjoc.6.62

• introduction of multiple fluorine atoms is often a cumbersome process, and in many cases a fluorinated building block approach [31][32] is more efficient. Known vicinal difluoride containing building blocks include (racemic) C2-symmetric and meso-2,3-difluorosuccinic acids (or esters) 1,2 (Figure 1) [9][22][23

New modification of the Perkow reaction: halocarboxylate anions as leaving groups in 3-acyloxyquinoline- 2,4(1H,3H)-dione compounds

• Oldřich Paleta,
• Karel Pomeisl,
• Stanislav Kafka,
• Antonín Klásek and
• Vladislav Kubelka

Beilstein J. Org. Chem. 2005, 1, No. 17, doi:10.1186/1860-5397-1-17

• -hydroxyquinolinediones (Scheme 3, R3 = CH2Br, Y = H). In order to investigate the potential changes in biological activity[11][12][13] of 10, we decided to introduce the fluorine substituent to the α-position of the butenolide ring (Scheme 3, 10, Y = F) utilizing the fluorinated building-block approach for the