Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• activate unsaturated bonds, and examples of olefin hydroalkylation, hydroarylation, hydrofluorination, hydroamination, and aminoheteroarylation, among others, can be found in the literature [36][37]. The first example of an olefin hydroalkylation promoted by gold catalysis appeared in 2004 in the work by

Activation of pentafluoropropane isomers at a nanoscopic aluminum chlorofluoride: hydrodefluorination versus dehydrofluorination

• Maëva-Charlotte Kervarec,
• Thomas Braun,
• Mike Ahrens and
• Erhard Kemnitz

Beilstein J. Org. Chem. 2020, 16, 2623–2635, doi:10.3762/bjoc.16.213

• –Crafts-like reactions to give with C6D6 11 or 3, which is consistent with previous studies [16]. The formation of the products described above (Scheme 4) involves consecutive reaction steps, such as dehydrofluorination, hydrodefluorination, hydrofluorination, allylic defluorination, hydroarylation, and

• treating 5 with HF was performed (Scheme 7, top), but the hydrofluorination product 6 was only detected in small amounts. In accordance with this result, the treatment of 6 in the presence of silane and ACF gave the dehydrofluorination product 5. The observations nevertheless suggest the presence of an

• was reported to be 1:0.8 starting from 4a [16]. This observation might be the result of a hydrofluorination reaction from 5 to 6. Moreover, in neat silane, 14 was not detected, whereas when less silane and a solvent was present, this product was observed. Due to a large amount of silane present, a

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• which they detailed the Markovnikov hydrofluorination of alkynes using HF.DMPU coupled with a gold catalyst [60]. Accordingly, the appropriate propargylmalonate derivatives were fluorinated to give fluoroalkene intermediates, which were then converted into malonate-based enynes 37 (Z = CO2R) through a

Cobalt bis(acetylacetonate)–tert-butyl hydroperoxide–triethylsilane: a general reagent combination for the Markovnikov-selective hydrofunctionalization of alkenes by hydrogen atom transfer

• Xiaoshen Ma and
• Seth B. Herzon

Beilstein J. Org. Chem. 2018, 14, 2259–2265, doi:10.3762/bjoc.14.201

• reduction conditions, alkene 3a was transformed to isobutyl p-methoxybenzoate (4a) in 86% yield (entry 1, Table 1). Inspired by the methods of Boger [12] and Hiroya [13], a number of fluorination reagents were examined to achieve hydrofluorination. Although no product was observed using SelectFluor

• ®, diethylaminosulfur trifluoride (DAST), or tosyl fluoride (see Supporting Information File 1, Table S1, entries 2–4), N-fluorobenzenesulfonimide (NFSI) provided the desired hydrofluorination product 4b in 36% yield (Table 1, entry 2). Carreira and co-workers reported the first hydrochlorination reaction via a cobalt

Fluorinated cyclohexanes: Synthesis of amine building blocks of the all-cis 2,3,5,6-tetrafluorocyclohexylamine motif

• Tetiana Bykova,
• Nawaf Al-Maharik,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2017, 13, 728–733, doi:10.3762/bjoc.13.72

• building blocks for discovery chemistry programmes. The synthesis starts from a Birch reduction of benzonitrile, followed by an in situ methyl iodide quench. The resultant 2,5-cyclohexadiene was progressed via double epoxidations and then hydrofluorination ring opening reactions. The resultant fluorohydrin

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

• Davide Bello and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

• Davide Bello David O'Hagan University of St Andrews, School of Chemistry, North Haugh, St Andrews, Fife, KY16 9ST, UK 10.3762/bjoc.11.205 Abstract A new method for the preparation of α-fluorovinyl thioethers is reported which involves the hydrofluorination of alkynyl sulfides with 3HF·Et3N, a

• thioester enols and enolates, important intermediates in enzymatic C–C bond forming reactions. The method opens access to appropriate analogues for investigations in this direction. Keywords: alkynyl sulfides; α-fluorovinyl thioethers; hydrofluorination; Lewis acids; organofluorine; Introduction

• , have a spatial and electrostatic profile consistent with the potential to mimic these enzyme intermediates. There is limited literature for preparing such analogues. We have previously described the preparation of α-fluorovinyl thioethers by hydrofluorination of the corresponding alkynyl sulfides using

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

• hydrofluorination of alkynes catalyzed by N-heterocyclic carbene gold(I) complexes [4], or by fluorodeauration of transient vinyl gold species [5][6], has been previously reported in the literature. On the basis of our recent results on the gold-catalyzed cyclization of enynes [7][8][9][10] and allenylhydrazones