Hydrazone–Cu‐Catalyzed Suzuki–Miyaura‐Type Reactions of Dibromoalkenes with Arylboronic Acids

1,3,2-diazaphospholenes hydrides (DAP-Hs) are highly nucleophilic organic hydrides serving as main-group catalysts for a range of attractive transformations. DAP hydrides can act as stoichiometric hydrogen atom transfer agents in radical reactions. Herein, we report a DAP-catalyzed reductive radical cyclization of a broad range of aryl and alkyl halides under mild conditions. The pivotal DAP catalyst turnover was achieved by a DBU-assisted σ-bond metathesis between the formed DAP halide and HBpin rapidly regenerating DAP H. The transformation is significantly accelerated by irradiation with visible light. Mechanistic investigations indicate that visible light irradiation leads to the formation of DAP dimers which are in equilibrium with the DAP radicals accelerating the cyclization. The direct use of (DAP)2 enabled a catalytic protocol in the absence of light.

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“…TLC (SiO2): Rf (n-pentane:EtOAc = 10:1) = 0.56 All spectroscopic data corresponded to the reported literature values. [29] (…”

Section: (±)-N-(2-hydroxypropyl)-4-methylbenzenesulfonamide (Si-11)mentioning

confidence: 99%

1,3,2-Diazaphospholene-Catalyzed Reductive Cyclizations of Organohalides

Cramer

Klett

Woźniak

2022

Preprint

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“…Transition-metal-catalyzed Hiyama coupling of organosilanes with halides has been developed as a routine tool for construction of new C-C bonds including the synthesis of the nonsymmetrical biaryls, 1,2 which are important materials for the preparation of polymers, agrochemicals, pharmaceutical intermediates, bioactive molecules, and electronic materials. [3][4][5][6] Compared to other organometallic reagents, [7][8][9][10] organosilicon reagents have emerged as more competitive nucleophilic partners for cross-coupling reactions due to their high chemical stability, low toxicity, and good compatibility. [11][12][13] Among the electrophiles employed in Hiyama coupling reactions, [14][15][16][17][18] halides exhibit relatively high reactivity, but they suffer from some drawbacks including harsh conditions for their preparation, with the formation of by-products and environmental pollution.…”

Section: Introductionmentioning

confidence: 99%

Palladium-catalyzed Hiyama cross-couplings of pyrimidin-2-yl tosylates with organosilanes

Gong

Quan

2022

Journal of Chemical Research

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An efficient palladium-catalyzed Hiyama reaction between various pyrimidin-2-yl tosylates with organosilanes has been developed. The use of CuCl with TBAF as additive is essential for promotion of the construction of the carbon–carbon bond. This procedure shows wide functional group tolerance for electrophilic pyrimidin-2-yl tosylates and has been extended to aromatic amino-substituted pyrimidin-2-yl tosylates, affording the desired C2-aryl and alkenyl pyrimidine derivatives in good to excellent yields.

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Synthesis of 7‐Allylated Benzofuran Derivatives from o‐Allyloxyethynylbenzene via Claisen Rearrangement and TBAF‐Catalyzed Annulation

et al. 2019

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The 7‐allylated benzofuran derivatives were synthesized via a continuous reaction of Claisen rearrangement and annulation using o‐allyloxyetynylbenzene as starting material. In addition, it was observed that annulation of o‐alkynylphenol proceeded under mild conditions when carried out in the presence of a catalytic amount of TBAF. Furthermore, these continuous reactions could be achieved in a one‐pot reaction and afforded not only 7‐allylbenzofurans but also 7‐alkenylbenzofurans by controlling the reaction temperature and time of the annulation. Finally, we demonstrated that 7‐allylbenzofuran and 7‐alkenylbenzofuran could be converted into 7‐(2‐formylvinyl)benzofuran and 7‐formylbenzofuran derivatives, respectively. Therefore, various 7‐substituted benzofuran derivatives could be synthesized according to this synthetic strategy.

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Hydrazone–Cu‐Catalyzed Suzuki–Miyaura‐Type Reactions of Dibromoalkenes with Arylboronic Acids

Cited by 4 publications

References 85 publications

1,3,2-Diazaphospholene-Catalyzed Reductive Cyclizations of Organohalides

1,3,2-Diazaphospholene-Catalyzed Reductive Cyclizations of Organohalides

Palladium-catalyzed Hiyama cross-couplings of pyrimidin-2-yl tosylates with organosilanes

Synthesis of 7‐Allylated Benzofuran Derivatives from o‐Allyloxyethynylbenzene via Claisen Rearrangement and TBAF‐Catalyzed Annulation

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