A copper‐catalyzed approach for the N‐acylation of anilines with acetone and acetophenones via C−C bond cleavage is described. Under the developed conditions both CHCl3 and CH2Cl2 were identified as ...potential C1‐source to promote the transformation. The reaction features a site selective C−C bond cleavage to install the amide moieties with high functional‐group compatibility and wide substrate scope. The developed method avoids the use of sensitive and narcotic agents. The method also represents an excellent complement to the previous protocols with lower E‐factor (13.91 mg/1 mg) than current industrially used method (E‐factor 17.54 mg/1 mg). The developed approach has also been extended for the effective preparation of pyridine derivatives and paracetamol in gram scale. The course of the reaction was monitored by 1H NMR as a preliminary investigation of the reaction mechanism.
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•Regioselective synthesis of β-oxo amides and 2‑quinolinones.•HFIP as a simple and cost-effective reagent.•Ferrites as a recyclable catalyst.•Intramolecular Friedel-Craft type ...cyclization.•Site-selective CN and CC bond formation.
A simple and cost-effective 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-mediated protocol for the synthesis of β-oxo amides has been described by using amines and β-keto esters as substrates. The reaction conditions were found to be highly efficient towards the cleavage of CO bond and consequent formation of the products in excellent yields and selectivity. The obtained β-oxo amides were further transformed in to the synthetically useful 2‑quinolinones via intramolecular Friedel-Craft type cyclization of aromatic ring using ferrites as a recyclable catalyst. A spectrum of substrates bearing broad range of functional groups were well tolerated under the reaction conditions. The proposed mechanistic pathways were substantially verified by literature and mass-spectroscopic evidences.
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•Transition-metal-free approach towards Glaser- and Cadiot-Chodkiewicz-type Coupling.•Regioselective synthesis of 1,3-diynes and 1,3-enynes.•Chemical transformations were possible in ...aqueous medium.•Organocatalyzed chemical transformations.•Broad substrate scope with high yields of the products.
Efficient and transition-metal-free transformations towards the synthesis of 1,3-diynes have been described from their corresponding terminal acetylenes or 1,1-dibromo-1-alkenes. The efficiency of molecular iodine as catalyst in aqueous medium, driven the transformation to afford 1,3-diynes in moderate to good yields. The developed reaction conditions revealed appreciable functional group tolerance in aqueous medium. Further, the scope of the transition-metal-free approach for the synthesis of 1,3-enynes has been investigated using terminal alkynes as easy available precursors.
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•No sensitive and hazardous reagents were used.•Reaction excludes the involvement of precious metals, additives, ligands and radical initiators.•Reaction proceeds without formation of ...any toxic side products.•Developed method utilizes 3-nitropyridine as organocatalyst under aerobic conditions.•Potential application for the synthesis of a broad range of compounds in excellent yields.
Copper‐catalyzed 2+2+1+1 annulation strategy has been investigated for the regioselective synthesis of symmetrical and unsymmetrical 2,6‐diarylpyridines using aliphatic amines as nitrogen source and ...DMSO as C1‐synthon. The developed protocol was successful for the transformation of non‐activated aromatic ketones and non‐activated aliphatic amines into 2,6‐diarylpyridines via an “easy to access” approach. This protocol has been verified on wide range of substrates having various functional groups.
A copper‐catalyzed 2+2+1+1 annulation protocol has been described via C1‐insertion and subsequent cyclization towards the comprehensive synthesis of 2,6‐diarylpyridines in good yields and selectivity using aliphatic amines as nitrogen and DMSO as C1 sources.
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•Rarely explored substrates have been investigated towards saturated N-heterocycles.•Developed method exclude the use of P(III) reagents for reductive cyclization.•Alternate source of ...molecular carbon monoxide has been used as sole reducing agent.
Using Pd/HCOOCs as a surrogate reagents synthesis of saturated N-heterocycles was described from nitroaromatics as starting materials. The developed new reaction conditions exclude the generally used toxic reagents like carbon monoxide as deoxygenative agent. The developed protocol permits the synthesis privileged bioactive N-heterocyclic scaffolds in good yields and selectivity.
Withdrawal: Malakar, C., Kabi, A., Gujjarappa, R., Vodnala, N. and Kaldhi, D. (2019), Gold‐Catalyzed Facile Protocol towards the Efficient Access of Azetidinyl Esters, β‐Amino Esters and δ‐Amino ...Esters using Simple Substrates, Asian J. Org. Chem., Accepted Article, Manuscript DOI: 10.1002/ajoc.201900319. The above article, first published online on 18 July 2019 in Wiley Online Library (wileyonlinelibrary.com), has been withdrawn by agreement between the authors, the journal′s Editor‐in‐Chief, and Wiley‐VCH GmbH & Co. KGaA. The withdrawal has been agreed due to concerns regarding the reported data, following a request by the authors.
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![Copper‐Catalyzed [2+2+1+1] ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2365-6549/small "Copper‐Catalyzed [2+2+1+1] Annulation for the Regioselective Synthesis of 2,6‐Diarylpyridines via C1‐Insertion and Subsequent Cyclization")
