Copper Salt Catalyzed Synthesis of Functionalized 2<i>H</i>‐Pyranes

Varmazyar, Alireza; Sedaghat, Sajjad; Golikand, Ahmad Nozad; Khalaj, Mehdi; Arab‐Salmanabadi, Samira

doi:10.1002/jhet.3570

Cited by 10 publications

(6 citation statements)

References 34 publications

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“…A copper-catalyzed three-component reaction between terminal alkynes, malonitrile, and oxiranes in HFIP affords functionalized 2 H -pyranes (Scheme ). The enhanced catalytic activity of copper(I) oxide (Cu 2 O) in this reaction was likely due to its improved solubility in HFIP; MeCN, DMF, and polyethylene glycols (PEG-200 and PEG-400) provided inferior yields. The authors applied a similar method for the synthesis of functionalized 2 H -pyran-5-carboxylate derivatives from malonates instead of malonitrile using (IPr)CuCl catalyst .…”

Section: Condensationsmentioning

confidence: 99%

HFIP in Organic Synthesis

et al. 2022

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1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) is a polar, strongly hydrogen bond-donating solvent that has found numerous uses in organic synthesis due to its ability to stabilize ionic species, transfer protons, and engage in a range of other intermolecular interactions. The use of this solvent has exponentially increased in the past decade and has become a solvent of choice in some areas, such as C–H functionalization chemistry. In this review, following a brief history of HFIP in organic synthesis and an overview of its physical properties, literature examples of organic reactions using HFIP as a solvent or an additive are presented, emphasizing the effect of solvent of each reaction.

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Section: Condensationsmentioning

confidence: 99%

HFIP in Organic Synthesis

et al. 2022

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“…Only a trace amount of the product 4a was obtained under the neat condition (entry 24). Interestingly and in contrast of the previous reports, the reaction exhibited excellent chemoselectivity and no products arising from the direct attack of copper acetylide on 3a are detected in crude reaction mixture analysis . Based on the spectroscopic analyses, all of the reactions proceeded through a 6‐exo cyclization path.…”

Section: Placeholder Textresults and Discussionmentioning

confidence: 64%

Copper‐catalyzed domino reaction between terminal alkynes, isocyanates, and oxiranes: An atom‐economic route to morpholine derivatives

Beigi‐Somar

Homami

Ghazanfarpour‐Darjani

et al. 2019

Journal of Heterocyclic Chem

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In situ generated copper acetylides react with isocyanates and oxiranes to form a decent range of morpholine derivatives. The reactions proceeded with acceptable yields and excellent regioselectivity. The presence of oxygen and moisture completely inhibited the reaction. The scope of the reaction is wide and the reactions involve consecutive C-C, C-N, and C-O bond formations. CDCl 3 ): δ H = 0.98 (9 H, s, 3 Me), 3.89 (1 H, dd, 2 J = 13.9 Hz, 3 J = 5.4 Hz, CH), 4.14 (1 H, dd, 2 J = 13.9 Hz, 3 J = 10.7 Hz, CH), 4.39 (1 H, dd, 3 J = 10.7, 5.4 Hz, CH), 6.54 (1 H, s, CH), 6.94 (1 H, t, 3 J = 7.6 Hz, CH), 7.31 (2 H, t, 3 J = 7.6 Hz, 2 CH), 7.35 (1 H, t, 3 J = 7.3 Hz, CH), 7.44 (2 H, t, 3 J = 7.3 Hz, 2 CH), 7.64 (2 H, d, 3 J = 7.3 Hz, 2 CH), 7.82 (2 H, d, 3 J = 7.6 Hz, 2 CH). 13 C NMR (125.7 MHz, CDCl 3 ):

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“…A pair of collaborative studies from the laboratories of Sedaghat and Khalaj have described three-component coupling / cyclization methods, combining terminal alkynes, epoxides, and the active methylene compounds malononitrile (89) or dimethyl malonate (90) (Table 10). 62,63 Several Cu(I) catalysts gave good to excellent yields of highly functionalized pyrans 91 or 92, corresponding to the active methylene reactant. In all cases, the best yields arose with HFIP as solvent, although satisfactory results were also reported with polyethylene glycol 400 (PEG 400, entries 5, 13).…”

Section: Ring-opening Reactions With Terminal Alkyne Nucleophilesmentioning

confidence: 99%

Fluorinated alcohols: powerful promoters for ring-opening reactions of epoxides with carbon nucleophiles

Dover¹,

McDonald²

2021

Arkivoc

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Ring-opening reactions of epoxides with carbon nucleophiles are valuable transformations for constructing functionalized carbon-carbon bonds. Epoxide ring-opening methods typically require Lewis acidic additives and/or strong nucleophiles to overcome the activation barrier for these reactions. Fluorinated alcohol solvents present a desirable alternative, enhancing the efficacy of these reactions with weak and neutral carbon nucleophiles by promoting electrophilic activation of the epoxide. We present here a thorough review of the literature regarding epoxide ring-opening reactions with carbon nucleophiles in fluorinated alcohol solvents, concluding with a few recent examples with aziridines.

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Copper Salt Catalyzed Synthesis of Functionalized 2H‐Pyranes

Cited by 10 publications

References 34 publications

HFIP in Organic Synthesis

HFIP in Organic Synthesis

Copper‐catalyzed domino reaction between terminal alkynes, isocyanates, and oxiranes: An atom‐economic route to morpholine derivatives

Fluorinated alcohols: powerful promoters for ring-opening reactions of epoxides with carbon nucleophiles

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