Highly Efficient and Stereoselective Radical Addition of Tertiary Amines to Electron-Deficient Alkenes − Application to the Enantioselective Synthesis of Necine Bases

Bertrand, Samuel; Hoffmann, Norbert; Pete, Jean‐Pierre

doi:10.1002/1099-0690(200006)2000:12<2227::aid-ejoc2227>3.0.co;2-8

Cited by 108 publications

(20 citation statements)

References 45 publications

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“…The resulting radical would carry a trimethylsilyl group, which would be eventually found in the product. The absence of a trimethylsilyl group in the products indicates that reduction (path a) and cyclization (path b) are more efficient than hydrogen abstraction while hydrogen abstraction has been established as a radical chain propagating step in reactions performed with UV light [5–6 8,11,32,34,38–40]. …”

Section: Results and Dicussionmentioning

confidence: 99%

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

Lenhart¹,

Bach²

2014

Beilstein J. Org. Chem.

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Summary N-Methyl-N-((trimethylsilyl)methyl)aniline was employed as reagent in visible-light-induced, iridium-catalyzed addition reactions to cyclic α,β-unsaturated carbonyl compounds. Typical reaction conditions included the use of one equivalent of the reaction substrate, 1.5 equivalents of the aniline and 2.5 mol % (in MeOH) or 1.0 mol % (in CH2Cl2) [Ir(ppy)2(dtbbpy)]BF4 as the catalyst. Two major reaction products were obtained in combined yields of 30–67%. One product resulted from aminomethyl radical addition, the other product was a tricyclic compound, which is likely formed by attack of the intermediately formed α-carbonyl radical at the phenyl ring. For five-membered α,β-unsaturated lactone and lactam substrates, the latter products were the only products isolated. For the six-membered lactones and lactams and for cyclopentenone the simple addition products prevailed.

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Section: Results and Dicussionmentioning

confidence: 99%

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

Lenhart¹,

Bach²

2014

Beilstein J. Org. Chem.

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“…The prevalence of 1,3- and 1,4-aminoketones and aminoalcohols in bioactive molecules renders this class of compounds a particularly attractive target for chemical synthesis. 6,7 Whereas the Mannich reaction has traditionally been the method of choice for generating 1,3-aminoketones via α -functionalization of carbonyl compounds, an analogous method for the synthesis of 1,4-aminoketones is heretofore unknown. 8 Herein, we report the successful completion of this goal through the development of a direct, photoredox organocatalytic β -aminoalkylation of saturated cyclic ketones, formally a β -Mannich protocol.…”

mentioning

confidence: 99%

Selective Radical–Radical Cross-Couplings: Design of a Formal β-Mannich Reaction

2015

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A direct β-coupling of cyclic ketones with imines has been accomplished via the synergistic combination of photoredox catalysis and organocatalysis. Transient β-enaminyl radicals derived from ketones via enamine and oxidative photoredox catalysis readily combine with persistent α-amino radicals in a highly selective hetero radical–radical coupling. This novel pathway to γ-aminoketones is predicated upon the use of DABCO as both a base and an electron transfer agent. This protocol also formally allows for the direct synthesis of β-Mannich products via a chemoselective three-component coupling of aryl aldehydes, amines, and ketones.

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“…A similar, simplified scenario is depicted in Scheme 8. Due to the comparable triplet energies of DMBP ( T 1 = 69.4 kcal/mol or 290 kJ/mol [53]) and phthalimides ( 2 : T 1 = 71 kcal/mol or 297 kJ/mol [39]), energy transfer (Scheme 8, path A) is not very efficient but has been confirmed spectroscopically for a related N -phthalimidocarboxylate/benzophenone pair [52]. Subsequent electron transfer (ET) from the carboxylate function to the triplet excited phthalimide furnishes an unstable carboxy radical, which undergoes rapid decarboxylation to the corresponding carbon radical.…”

Section: Resultsmentioning

confidence: 99%

Microphotochemistry: 4,4'-Dimethoxybenzophenone mediated photodecarboxylation reactions involving phthalimides

Shvydkiv¹,

Nolan²,

Oelgemöller³

2011

Beilstein J. Org. Chem.

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SummaryA series of 4,4'-dimethoxybenzophenone mediated intra- and intermolecular photodecarboxylation reactions involving phthalimides have been examined under microflow conditions. Conversion rates, isolated yields and chemoselectivities were compared to analogous reactions in a batch photoreactor. In all cases investigated, the microreactions gave superior results thus proving the superiority of microphotochemistry over conventional technologies.

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Highly Efficient and Stereoselective Radical Addition of Tertiary Amines to Electron-Deficient Alkenes − Application to the Enantioselective Synthesis of Necine Bases

Cited by 108 publications

References 45 publications

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

Selective Radical–Radical Cross-Couplings: Design of a Formal β-Mannich Reaction

Microphotochemistry: 4,4'-Dimethoxybenzophenone mediated photodecarboxylation reactions involving phthalimides

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