Cu-Pybox catalyzed synthesis of 2,3-disubstituted imidazo[1,2-a]pyridines from 2-aminopyridines and propargyl alcohol derivatives

Cheng, Cang; Ge, Luo; Lu, Xuehe; Huang, Jianping; Huang, Haocheng; Chen, Jie; Cao, Weiguo; Wu, Xiaoyu

doi:10.1016/j.tet.2016.09.013

Cited by 13 publications

(7 citation statements)

References 62 publications

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“…Figure b indicates that electron-rich phosphines are superior to electron-deficient phosphines possibly because electron-rich phosphine can facilitate the cleavage of the propargylic C–O bond when Cu-2 is converted to Cu-3 . Unlike other copper-catalyzed propargylation methods performed in aprotic solvents, − polydentate ligands did not accelerate the reaction in water in this study. Therefore, the copper-catalyzed propargylic C–O bond cleavage in water requires different ligand design principles.…”

Section: Results and Discussioncontrasting

confidence: 60%

“…This phosphine did not render other metals, including palladium, reactive toward PPE. Copper-catalyzed propargylic C–O bond cleavage has been known in synthetic chemistry, but the ligands were mostly amines or amine–phosphine hybrids and were designed for stereoselectivity. − Additionally, fluorescent probes for copper ions are primarily based on sulfides and amines as the binding motifs. − The reaction of copper with PPE in the presence of phosphines 2 , 15 , 18 , and 34 resulted in a fluorescence increase of 2-fold or more (Table S2). It appears that electron-rich phosphines were more effective.…”

Section: Results and Discussionmentioning

confidence: 99%

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Using Ligand-Accelerated Catalysis to Repurpose Fluorogenic Reactions for Platinum or Copper

et al. 2020

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The development of a fluorescent probe for a specific metal has required exquisite design, synthesis, and optimization of fluorogenic molecules endowed with chelating moieties with heteroatoms. These probes are generally chelation- or reactivity-based. Catalysis-based fluorescent probes have the potential to be more sensitive; however, catalytic methods with a biocompatible fluorescence turn-on switch are rare. Here, we have exploited ligand-accelerated metal catalysis to repurpose known fluorescent probes for different metals, a new approach in probe development. We used the cleavage of allylic and propargylic ethers as platforms that were previously designed for palladium. After a single experiment that combinatorially examined >800 reactions with two variables (metal and ligand) for each ether, we discovered a platinum- or copper-selective method with the ligand effect of specific phosphines. Both metal–ligand systems were previously unknown and afforded strong signals owing to catalytic turnover. The fluorometric technologies were applied to geological, pharmaceutical, serum, and live cell samples and were used to discover that platinum accumulates in lysosomes in cisplatin-resistant cells in a manner that appears to be independent of copper distribution. The use of ligand-accelerated catalysis may present a new blueprint for engineering metal selectivity in probe development.

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Section: Results and Discussioncontrasting

confidence: 60%

Section: Results and Discussionmentioning

confidence: 99%

Using Ligand-Accelerated Catalysis to Repurpose Fluorogenic Reactions for Platinum or Copper

et al. 2020

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“…In 2016, Wu and co-workers reported an example of Cu-Pybox catalyzed synthesis of 2,3-disubstituted imidazo[1,2-b] pyridazine 8. [72] Thus, when 3-aminopyridazine was treated with 1-phenylprop-2-yn-1-yl acetate in the presence of catalytic amount of copper(II) acetylacetonate, Pybox ligand and N,Ndiisopropyléthylamine (DIPEA) as the base in methanol at room temperature, the desired imidazo[1,2-b]pyridazine 8 was obtained in good yield (Scheme 5). Similarly, under the optimized conditions, N-heterobicyclic compounds such as substituted imidazo[1,2-a]pyridines, imidazo[1,2-c]pyrimidines, imidazo[1,2a]pyrazines, and imidazo[1,2-a]pyrimidines, were prepared in moderate to excellent yields.…”

Section: Copper-catalyzed Oxidative Cyclization Of Imidazo[12-b] Pyridazinesmentioning

confidence: 99%

Synthesis and Functionalization of Imidazo[1,2‐b]Pyridazine by Means of Metal‐Catalyzed Cross‐Coupling Reactions

et al. 2021

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This review surveys the recent developments in organometallic-chemistry-based methods for the preparation of imidazo [1,2-b]pyridazines by cyclization as well as their functionalization by means of cross-coupling reactions such as Sonogashira, Heck, Negishi, Suzuki-Miyaura, Kumada and Stille. In addition, the advances made on the CÀ H activation of imidazo[1,2-b] pyridazines using C-arylation, C-benzylation and C-alkylation are also reviewed. Furthermore, the recent reports on the Narylation of this heterocyclic system are discussed and highlighted. The sequential couplings as well as the one-pot functionalization of two different positions on the imidazo[1,2b]pyridazine systems are also reviewed. Procedures in which metal-based catalysis is not involved in the functionalization of imidazo [1,2-b]pyridazines are not included in this review.(MTCC 3382), Staphylococcus aureus (MTCC 3160), Bacillus subtilis (MTCC 297), and Gram-negative bacteria: Pseudomonas aeruginosa (MTCC 1034), Klebsiella pneumoniae (MTCC).

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“…用于与 2-氨基吡啶进行成环反应的底物中, 芳基炔有机化学综述与进展类化合物也较为常见 [52] . 此时 , 通常需要金属催化剂 [53] , 尤其是铜类催化剂 [54] . 其中, CuI 比较常见.…”

Section: 以芳基炔类、烯类等化合物为原料unclassified

Application of 2-Aminopyridines in the Synthesis of Five- and Six-Membered Azaheterocycles

Chen¹,

Chen²,

Wu³

et al. 2021

Chinese Journal of Organic Chemistry

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2-Aminopyridine is a significant synthetic synthon, with unique dual nucleophilic structure. It can react with ketones, aldehydes, acids, multifunctional esters, halogenated aromatics and other compounds to synthesize five-and six-member azaheterocycles. In recent years, the cyclization reactions based on 2-aminopyridines have been under the spotlight. According to the different types of substrates, the research progress on the synthesis of imidazo[1,2-a]pyridines and pyrido[1,2-a]pyrimidines based on 2-aminopyridines in the past 5 years is reviewed, and its applications in organic synthesis methodology, drug synthesis and fluorescent probes are summarized. Furthermore, the development trend of green cyclization and its application based on 2-aminopyridines in the future are prospected. Keywords 2-aminopyridine; imidazo[1,2-a]pyridine; pyrido[1,2-a]pyrimidine; azaheterocycle; C-N bond formation; retrosynthetic analysis 吡啶环上氮原子具有较强的吸电子效应, 且吡啶 α 位基团具有特殊的作用, 使吡啶 α 位的衍生物作为合成子或中间体在有机合成、药物合成中日益引人瞩目 [1][2][3] . 其中, 2-氨基吡啶作为最典型的一种, 因其独特的双亲核结构特点为人们所重视 [4] , 特别是基于吡啶环上的氮与氨基的成环反应倍受关注 [5][6][7] .

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Cu-Pybox catalyzed synthesis of 2,3-disubstituted imidazo[1,2-a]pyridines from 2-aminopyridines and propargyl alcohol derivatives

Cited by 13 publications

References 62 publications

Using Ligand-Accelerated Catalysis to Repurpose Fluorogenic Reactions for Platinum or Copper

Using Ligand-Accelerated Catalysis to Repurpose Fluorogenic Reactions for Platinum or Copper

Synthesis and Functionalization of Imidazo[1,2‐b]Pyridazine by Means of Metal‐Catalyzed Cross‐Coupling Reactions

Application of 2-Aminopyridines in the Synthesis of Five- and Six-Membered Azaheterocycles

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