Selectivity in cyclopropanations and 1,3-cycloadditions in transition metal-catalyzed decompositions of 2-diazocyclohexane-1,3-diones and the corresponding phenyliodonium ylides

Müller, Paul; Allenbach, Yves; Ferri, Maria; Bérnardinelli, Gerald

doi:10.3998/ark.5550190.0004.709

Cited by 26 publications

(12 citation statements)

References 11 publications

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“… Dirhodium(II,II) complexes containing O , O '‐bridging ligands with structural motive OOCCHHetR; Het=nitrogen, R=alkyl or aryl (cyclic α‐amino acid derivatives): T1 , [182] T2 , [182] T3 , [232] T4 , [182] T5 , [223] T6 , [233] T7 , [233] T8 , [234] T9 , [234] T10 , [234] T11 , [234] T12 , [234] T13 , [234] T14 , [234] T15 , [234] T16 , [234] T17 , [234] T18 , [234] T19 , [234] T20 , [234] T21 , [234] T22 , [234] T23 , [234] T24 , [234] T25 , [234] T26 , [234] T27 , [234] T28 , [234] T29 , [235] T30 [235] …”

Section: Overview Of Rh2a4 Paddlewheel Complexesmentioning

confidence: 99%

“… Dirhodium(II,II) complexes containing O , O '‐bridging ligands with structural motive OOCCHHetR; Het=nitrogen, R=tertiary substituent: V1 , [230] V2 , [231] V3 , [231] V4 , [239] V5 , [239] V6 , [240] V7 , [241] V8 , [236] V9 , [242] V10 , [243] V11 , [239] V12 , [244] V13 , [245] V14 , [246] V15 , [239] V16 , [227] V17 , [231] V18 , [235] V19 , [247] V20 , [247] V21 , [247] V22 , [229] V23 , [229] V24 , [248] V25 , [249] V26 [248] …”

Section: Overview Of Rh2a4 Paddlewheel Complexesmentioning

confidence: 99%

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Dirhodium(II,II) Paddlewheel Complexes

Hrdina

2021

Eur J Inorg Chem

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This minireview summarizes synthetic approaches towards homoleptic dirhodium(II,II) paddlewheel complexes with the general formula Rh2A4. These complexes have found numerous applications in a wide range of chemical research and industry as catalysts, detectors, enzymatic inhibitors or building blocks for molecular scaffolds. In organic synthesis they are commonly used to transfer electron‐deficient species, they act as Lewis acids to activate unsaturated bonds, serve as hydrogenation catalysts and participate in oxidation/reduction processes. Dirhodium paddlewheel complexes are composed of the Rh‐Rh backbone and four bridging anions, which surround the core. According to the application, the electrochemical potential of the Rh atom can be modulated, as can the geometry and physical and chemical properties of the metal complex. Dirhodium complexes can be prepared in one step from basic inorganic precursors or by post‐functionalization of the paddlewheel structures.

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Section: Overview Of Rh2a4 Paddlewheel Complexesmentioning

confidence: 99%

Section: Overview Of Rh2a4 Paddlewheel Complexesmentioning

confidence: 99%

Dirhodium(II,II) Paddlewheel Complexes

Hrdina

2021

Eur J Inorg Chem

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“…The cycloaddition to ethyl vinyl ether (8) proceeded by analogy to 9 in 78% yield (Scheme 2), but with lower enantioselectivity, while yield and enantioselectivity dropped with the more hindered t-butyl vinyl ether (10). Dihydropyran (12), in turn, underwent cycloaddition to 13 4b with lower yield and selectivity than dihydrofuran (2).…”

Section: Methodsmentioning

confidence: 99%

Ru-Catalyzed Enantioselective Dipolar Cycloadditions of Ethyl Diazopyruvate

Chappellet¹,

Müller²

2004

Synlett

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The decomposition of ethyl diazopyruvate (1) with [RuCl 2 (pybox)] catalysts in the presence of enol ethers affords dihydrofurans derived from formal 1,3-cycloaddition. Enantioselectivities of up to 74% have been achieved.The transition metal-catalyzed decomposition of diazoketones or diazoesters in the presence of olefins affords cyclopropanes. A large variety of catalytic systems, based mainly on copper 1 and rhodium, 2 are available for enantioselective cyclopropanations. Furthermore, diazo compounds carrying electron-accepting substituents such as ethyl diazoacetoacetate, 3 ethyl diazopyruvate, 4 or 2-diazocyclohexane-1,3-dione, 5 or the corresponding phenyliodonium ylides 6 may react with olefins by formal 1,3-cycloaddition to afford dihydrofuran derivatives. The cycloaddition occurs typically with enol ethers, enol acetates, furans and other polarizable olefins, but may also be observed with acetylenes 7 and even with styrene. 8 Pirrung, and subsequently Ishitani and Achiwa, reported enantioselective cycloadditions of 2-diazocyclohexane-1,3-dione or 2-diazodimedone to furan and dihydrofuran, respectively. 9Recently, we have re-examined cycloadditions of 2-diazocyclohexane-1,3-dione to dihydrofuran with a large selection of structurally different chiral rhodium(II) catalysts. 8a,10 However, to our disappointment the reactions proceeded with no, or at best, with very modest enantioselectivity, and we were unable to reproduce the results reported by Pirrung and Ishitani under the conditions used by these authors. This failure was tentatively attributed to the highly electrophilic nature of the intermediate metallocarbene, which is a consequence of the additional electron-withdrawing carbonyl substituent. In contrast, carbenes carrying electron-donating substituents proceed through later transition states as evidenced by their higher r-value in Rh(II)-catalyzed cyclopropanations of styrene, and these latter carbenes are also more enantioselective. 11 Unfortunately, they are in general inappropriate for the preparation of dihydrofurans, although there are exceptions. 12 In view of this, we turned our attention to Ru catalysts. Complexes of ruthenium have been found to catalyze the cyclopropanation of certain olefins effectively, and high levels of asymmetric induction can be realized. Ruthenium has emerged as the third important metal for the carbenoid decomposition of diazo compounds besides copper and rhodium. 13 We were struck by the high r-value of -2.5 for the cyclopropanation of styrene with [RuCl(pnnp)] + reported by Mezzetti. 14 This high negative reaction constant suggested that the Ru complexed carbenes might be more selective than the Rh analogues.Preliminary experiments using 2-diazodimedone as substrate and [RuCl 2 (p-cymene)] 2 in conjunction with Mezzetti's pnnp ligand (7) 14 or with the pybox ligand of Nishiyama 15 were not satisfactory, however. 16 The catalysts were not sufficiently reactive to decompose the diazo precursors efficiently, although encouraging enantioselectivities were obtaine...

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“…60,64,73,74,88 For example, the copper(II)-catalyzed intramolecular C-H insertion of phenyliodonium ylide 49 in the presence of chiral ligands followed by hydrolysis and decarboxylation affords product 50 in moderate yield with up to 72% ee (Scheme 15).…”

Section: Scheme 14 Intramolecular Cyclization Of Phenyliodonium Ylidmentioning

confidence: 99%

Iodonium ylides in organic synthesis

Yusubov

Yoshimura

Zhdankin³

2016

Arkivoc

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This review summarizes the chemistry of iodonium ylides with emphasis on their synthetic applications. The preparation, structure and chemistry of iodonium ylides of different structural types are overviewed. Iodonium ylides have found synthetic application as efficient carbene precursors, especially useful as reagents for cyclopropanation of alkenes and preparation of heterocyclic compounds. Recently iodonium ylides have been utilized as efficient reagents in the thiotrifluoromethylation and nucleophilic fluorination reactions.

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Selectivity in cyclopropanations and 1,3-cycloadditions in transition metal-catalyzed decompositions of 2-diazocyclohexane-1,3-diones and the corresponding phenyliodonium ylides

Cited by 26 publications

References 11 publications

Dirhodium(II,II) Paddlewheel Complexes

Dirhodium(II,II) Paddlewheel Complexes

Ru-Catalyzed Enantioselective Dipolar Cycloadditions of Ethyl Diazopyruvate

Iodonium ylides in organic synthesis

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