Radical ion cyclizations

Hintz, Sandra; Heidbreder, Andreas; Mattay, Jochen

doi:10.1007/3-540-60110-4_3

Cited by 43 publications

(34 citation statements)

References 220 publications

(176 reference statements)

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“…Both radical cations and radical anions exhibit intriguing, synthetically useful reactivity that is often not available to closed-shell organic molecules. − However, in photoredox catalysis, it is relatively rare for both radical ion equivalents to be simultaneously engaged in the same organic transformation. More commonly, a single synthetically relevant organic substrate is activated by photoinduced electron transfer, and a balancing redox equivalent is independently introduced to the reaction.…”

Section: Photoinduced Electron Transfermentioning

confidence: 99%

Dual Catalysis Strategies in Photochemical Synthesis

2016

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The interaction between an electronically excited photocatalyst and an organic molecule can result in the genertion of a diverse array of reactive intermediates that can be manipulated in a variety of ways to result in synthetically useful bond constructions. This Review summarizes dual-catalyst strategies that have been applied to synthetic photochemistry. Mechanistically distinct modes of photocatalysis are discussed, including photoinduced electron transfer, hydrogen atom transfer, and energy transfer. We focus upon the cooperative interactions of photocatalysts with redox mediators, Lewis and Brønsted acids, organocatalysts, enzymes, and transition metal complexes.

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Section: Photoinduced Electron Transfermentioning

confidence: 99%

Dual Catalysis Strategies in Photochemical Synthesis

2016

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“…(Z)-3-Cyclodecen-1-one (30) ]dodeca-1(8),9,11-triene (9): Compound 9 (1.57 g, 6.37 mmol) and DCN (398 mg, 2.33 mmol)) were dissolved in acetonitrile (500 mL) and irradiated in an immersion well reactor according to GP I for 84 h. The crude product was filtered over silica gel (cyclohexane/ethyl acetate 85:15) and purified by HPLC (cyclohexane/ethyl acetate 90:10) yielding 6-methyl-6,7,8,9-tetrahydro-5H-benzo[a]cyclohepten-5-one (32; 366 mg, 34 %) and 3-propyl-1-indanone (33; 125 mg, 11 %) as colorless oils. 34±1.48 (m, 3 H, 1'-H/2'-H), 1.86 (m, 1 H, 1'-H , 1 H, 2-H …”

Section: -(2-propenylmentioning

confidence: 99%

“…, 163 (3), 162 (21), 161 (8), 149 (7), 148 (50), 147 (31), 146 (10), 145 (8), 144 (6), 143 (4), 135 (3), 134 (19), 133 (29), 132 (3), 131 (6), 130 (11), 129 (5), 121 (5), 120 (12), 119 (16), 118 (4), 117 (10), 115 (4), 108 (6), 107 (8), 106 (14), 105 (29), 104 (31), 103 (6), 96 (3), 95 (30), 94 (16), 93 (22), 92 (37), 91 (100), 81 (17), 80 (23), 79 (65), 78 (26), 77 (48), 68 (3), 67 (19), 66 (7), 65 (16), 55 (11), 54 (3), 53 (13), 52 (4), 51 (7), 43 (4), 42 (4), 41 (39), 40 (4), 39 (21) …”

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Synthetic Applications in Radical/Radical Cationic Cascade Reactions

Rinderhagen

Mattay

2004

Chemistry A European J

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Oxidative photoinduced electron transfer (PET) reactions have been performed with various cyclic cyclopropyl(vinyl) silyl ethers bearing an olefinic or acetylenic side chain. The reactions result in bi- to tetracyclic ring systems via a fragmentation-radical/radical cationic addition reaction pathway with well defined ring juncture. The mode of cyclisation (endo/exo) can be partially controlled by addition of nucleophiles due to the suppression of radical cationic reaction pathways. Quantum chemical calculation of the cyclisation transition states underline the experimentally found selectivities. Additional mechanistic studies concerning the saturation step reveal that the final radical is saturated mostly by the solvent and traces of water in the solvent.

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“…Numerous electron transfer cyclization reactions (e.g. the biomimetic tandem cyclizations of polyenes) 19 can be written on paper as leading to carbon radicals which have to catch a hydrogen from somewhere to give the final products. In many cases the assumption of a secondary electron transfer can solve this query.…”

Section: Methodsmentioning

confidence: 99%

Synthetic Applications of Photoinduced Electron Transfer Decarboxylation Reactions

Griesbeck

Krämer

Oelgemöller

1999

Synlett

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Photoinduced electron transfer (PET) decarboxylation of alkyl carboxylates in water leads to primary, secondary or tertiary carbon radicals which undergo C-C coupling reactions either in an intra-or intermolecular fashion. Intramolecular coupling gives rise to heterocyclic ring systems (lactams, lactones, cyclopeptides, cyclic ethers, crown ethers) with ring sizes from 5 to 28 and a broad variety of functionalities. Intermolecular coupling gives Grignardtype adducts (but with different chemo-and regioselectivities as for carbanion reactions). Yields of these reactions are mostly high, dilution conditions are not necessary, quantum yields are in the range of 0.5-0.6, and chemo-as well as regioselectivities are excellent. The electron-accepting chromophores which have been investigated are the imides of phthalic, maleic, quinolinic and trimellitic acid.Selectivity can be further controlled by two simple tricks:-Only triplet excited acceptors are active in these electron-transfer reactions, thus sensitization excludes other (homolytic) pathways; -Donor groups (SR, NR 2 , aryl, OR, C=C) other than the carboxylate can be activated by lowering the pH (and thus protonating the COO-donor).In intramolecular reactions, substrate concentration up to 0.1 M were applied successfully and the reactions were completed in 10-12 h for multigram conversions.

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Radical ion cyclizations

Cited by 43 publications

References 220 publications

Dual Catalysis Strategies in Photochemical Synthesis

Dual Catalysis Strategies in Photochemical Synthesis

Synthetic Applications in Radical/Radical Cationic Cascade Reactions

Synthetic Applications of Photoinduced Electron Transfer Decarboxylation Reactions

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