Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• ) radicals. Since the dawn of organic chemistry, several radical decarboxylations have been developed, including the Kolbe electrolysis [33][34], the Hunsdiecker reaction [35], and the Barton decarboxylation [36][37][38]. More recently, photoredox catalysis has appeared as a mild alternative to these

Diastereoselective anodic hetero- and homo-coupling of menthol-, 8-methylmenthol- and 8-phenylmenthol-2-alkylmalonates

• Matthias C. Letzel,
• Hans J. Schäfer and
• Roland Fröhlich

Beilstein J. Org. Chem. 2017, 13, 33–42, doi:10.3762/bjoc.13.5

• . Keywords: anodic decarboxylation; diastereoselectivity; Kolbe electrolysis; radical hetero-coupling; radical homo-coupling; Introduction Intermolecular radical additions with high diastereoselectivity have been described for a number of cases [1][2][3][4][5][6][7][8][9]. There are much fewer reports on

• literature [25], where the oxidation potential for anisole and toluene was determined to be 1.15 V and 1.35 V (vs Ag/Ag+), respectively. In the Kolbe electrolysis a critical potential of 1.9 to 2.2 V (vs Ag/AgCl) has to be exceeded. At this potential the coverage of the electrode with carboxylate ions

• increases sharply, the oxygen evolution is inhibited, solvent oxidation is retarded and the Kolbe electrolysis is promoted [26]. If in the carboxylate an additional electrophore with a lower oxidation potential than the critical potential is present it is oxidized instead of the carboxylate group. This is

Anodic coupling of carboxylic acids to electron-rich double bonds: A surprising non-Kolbe pathway to lactones

• Robert J. Perkins,
• Hai-Chao Xu,
• John M. Campbell and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2013, 9, 1630–1636, doi:10.3762/bjoc.9.186

• taken because of the well-known Kolbe electrolysis reaction (Scheme 3) [10][11]. In the Kolbe electrolysis (Scheme 3, reaction 1), a carboxylic acid is oxidized. A decarboxylation reaction then leads to the formation of a radical that is subsequently trapped by a second radical formed in solution. The

• . Radical cation stabilization by an o-methoxy substituent. General scheme for anodic cyclization reactions. Anodic cyclization competition study. Kolbe electrolysis reactions. Oxidative coupling between a carboxylic acid and electron-rich olefin. Predicted relative rates of single-electron oxidation based

A practical microreactor for electrochemistry in flow

• Kevin Watts,
• William Gattrell and
• Thomas Wirth

Beilstein J. Org. Chem. 2011, 7, 1108–1114, doi:10.3762/bjoc.7.127

• the reduction of methanol at the cathode. The Kolbe electrolysis of 6a has also been described as a batch reaction, with a solid base, providing the product 7a in 44% yield [19]. This means that the reaction conditions in the electrochemical microreactor were comparable to batch synthesis. The

• ) through a syringe pump (flow rate 80 µL/min; residence time: 7 s) with an applied current of 2 mA (current density: 1.11 mA/cm2) and collected at the outlet to give 5 after removal of the solvent. The product was identified by GC/MS m/z (EI): M+ 129.1. Kolbe electrolysis A 0.1 M solution of 2-phenylacetic

• C16H18I, 337.0448; found, 337.0444. Electrochemical microreactor. Electrochemically generated N-acyliminium ions 1 and subsequent reactions. Electrolysis of furan. Kolbe electrolysis of phenylacetic acids 6 in flow. Synthesis of diaryliodonium salts 11 in flow. Products and yields in the electrochemical