A Metal-Free Approach for the Synthesis of 2-Tetralones via Carbanion-Induced Ring Transformation of 2H-Pyran-2-ones

Synthesis ◽  
2018 ◽  
Vol 50 (17) ◽  
pp. 3540-3548 ◽  
Author(s):  
Fateh Singh ◽  
Samata Shetgaonkar
Keyword(s):  
Functional Groups ◽  
Ring Transformation ◽  
Organometallic Reagents ◽  
Metal Free ◽  
Wide Range ◽  
Ultrasound Assisted ◽  
High Yields ◽  
Subsequent Acid

A metal-free, ultrasound-assisted approach for the synthesis of highly functionalized 2-tetralones in high yields is described. The process involves ring transformation of 2H-pyran-2-ones with the spirocyclic ketone 1,4-cyclohexandione monoethylene ketal to yield spiro­cyclic ketals and subsequent acid-mediated hydrolysis. This protocol is free from any organometallic reagents, is economical and tolerates a wide range of functional groups.

Metal-free [3+3] benzannulation of 1-indanylidene-malononitrile with Morita–Baylis–Hillman carbonates: direct access to functionalized fluorene and fluorenone derivatives

2020 ◽  
Vol 56 (13) ◽  
pp. 1948-1951 ◽  
Author(s):  
Ya-Sa Xie ◽  
Run-Feng Huang ◽  
Ran Li ◽  
Chuan-Bao Zhang ◽  
Ji-Ya Fu ◽  
...  
Keyword(s):  
Direct Access ◽  
Metal Free ◽  
Wide Range ◽  
High Yields

An efficient [3+3] benzannulation of Morita–Baylis–Hillman carbonates with 1-indanylidenemalononitrile was achieved selectively delivering a wide range of functional fluorene or fluorenone compounds in high yields (up to 86% yields).

Mild and Direct C–H Arylation of Quinoxalin-2(1H)-ones with Aryldiazonium Salts under Metal-Free Conditions

Synlett ◽  
2017 ◽  
Vol 29 (05) ◽  
pp. 597-602 ◽  
Author(s):  
Ronghua Zhang ◽  
Kun Yin
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Environmental Friendliness ◽  
Metal Free ◽  
Wide Range

A mild and direct C–H arylation of quinoxazolin-2(1H)-ones with aryldiazonium salts has been developed. A wide variety of 3-arylquinoxazolin-2(1H)-ones were synthesized in up to 92% yield at room temperature under metal-free conditions. This strategy tolerates a wide range of functional groups and shows environmental friendliness and practicality.

scholarly journals Direct access to multi-functionalized benzenes via [4 + 2] annulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes

RSC Advances ◽  
2020 ◽  
Vol 10 (49) ◽  
pp. 29171-29174 ◽  
Author(s):  
Qianfa Jia ◽  
Yunfei Lan ◽  
Xin Ye ◽  
Yinhe Lin ◽  
Qiao Ren
Keyword(s):  
Direct Access ◽  
Reaction Conditions ◽  
Metal Free ◽  
Unsaturated Aldehydes ◽  
Wide Range ◽  
High Yields

An efficient [4 + 2] benzannulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes was achieved under metal-free reaction conditions selectively delivering a wide range of polyfunctional benzenes in high yields respectively (up to 94% yield).

Efficient Synthesis of Diaryl Sulfides by Copper-catalysed Coupling of Aryl Halides and Thioacetate in Water

2013 ◽  
Vol 37 (1) ◽  
pp. 19-21 ◽  
Author(s):  
Yimin Zhang ◽  
Iiu ◽  
Junmin Chen
Keyword(s):  
Functional Groups ◽  
Catalytic System ◽  
Aryl Halides ◽  
Efficient Synthesis ◽  
Highly Efficient ◽  
Wide Range ◽  
High Yields

A simple economical, and highly efficient catalytic system for the synthesis of diaryl sulfides by a copper-catalysed coupling of aryl halides and thioacetate in water has been developed. A variety of aryl halides reacted with thioacetate to give the desired products in high yields up to 95%. The present catalysis protocol tolerated a wide range of functional groups, including amino, fluoro, and carboxyl moieties.

Iodide-Catalyzed Carbonylation–Benzylation of Benzyl Chlorides with Potassium Aryltrifluoroborates under Ambient Pressure of Carbon Monoxide

Synlett ◽  
2017 ◽  
Vol 29 (03) ◽  
pp. 369-374 ◽  
Author(s):  
Wei Han ◽  
Junjie Chen ◽  
Fengli Jin ◽  
Xiaorong Yuan
Keyword(s):  
Carbon Monoxide ◽  
Ambient Pressure ◽  
The Novel ◽  
Metal Free ◽  
Benzyl Chlorides ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Method ◽  
High Yields ◽  
Co Gas

Tetra-N-butylammonium iodide (TBAI) catalyzed carbonylation–benzylation of unactivated benzyl chlorides with potassium aryltrifluoroborates using CO gas has been developed. This reaction is transition-metal free, is carried out under ambient pressure, and provides a wide range of 1,2,3-triarylpropan-1-one derivatives in high yields. The novel method represents a significant improvement over the traditional palladium-catalyzed carbonylation.

Transition-Metal-Free Synthesis of Trifluoromethylated Furans via a Bu3P-Mediated Tandem Acylation–Wittig Reaction

Synlett ◽  
2020 ◽  
Vol 31 (20) ◽  
pp. 2035-2038
Author(s):  
Wei Zhou ◽  
Maizhan Li
Keyword(s):  
Transition Metal ◽  
Functional Groups ◽  
Nucleophilic Addition ◽  
Wittig Reaction ◽  
Reaction Conditions ◽  
Metal Free ◽  
Highly Efficient ◽  
Intramolecular Wittig Reaction ◽  
High Yields

AbstractA highly efficient nucleophilic addition–O-acylation–intramolecular Wittig reaction of β-trifluoromethyl α,β-enones is disclosed. This strategy features mild reaction conditions and provides a practical transition-metal-free method to a set of biologically significant trifluoromethylated furans in high yields with diverse functional groups.

A Fast and Direct Iodide-Catalyzed Oxidative 2-Selenylation of Tryptophan

2021 ◽  
Author(s):  
Yu-Ting Gao ◽  
Shao-Dong Liu ◽  
Liang Cheng ◽  
Li Liu
Keyword(s):  
Functional Groups ◽  
Metal Free ◽  
High Yields ◽  
Tryptophan Derivatives

A metal-free 2-selenylation of tryptophan derivatives is reported, where the use of iodide as the catalyst and oxone as the oxidant is key to obtain high yields. Various functional groups...

scholarly journals Metal-Free Synthesis of Biaryl- and Teraryl-Cored Diarylmethanes by Ring Transformation of 2H-Pyran-2-ones

Synthesis ◽  
2018 ◽  
Vol 51 (06) ◽  
pp. 1435-1444 ◽  
Author(s):  
Fateh Singh ◽  
Priyanka Kole
Keyword(s):  
Reaction Products ◽  
Ring Transformation ◽  
Reaction Conditions ◽  
Metal Free ◽  
High Yields

An efficient metal-free approach for the synthesis of functionalized biaryl-cored diarylmethanes is described by the ring transformation of 2H-pyran-2-ones using 4-phenylbutan-2-one as carbanion source. Moreover, 2H-pyran-2-ones were reacted with 1,3-diphenylacetone in the presence of base to achieve functionalized teraryl-cored diarylmethanes. All the ring transformation reactions were performed under mild reaction conditions to afford the biaryl- and teraryl-cored reaction products in high yields.

Coupling of N-Nosylhydrazones with Nitrosoarenes: Transition-Metal-Free Approach to (Z)-N-Arylnitrones

Synthesis ◽  
2018 ◽  
Vol 50 (08) ◽  
pp. 1728-1736 ◽  
Author(s):  
Tingting Liu ◽  
Zhaohong Liu ◽  
Zhenhua Liu ◽  
Donghua Hu ◽  
Yeming Wang
Keyword(s):  
Transition Metal ◽  
Functional Groups ◽  
Direct Coupling ◽  
Recrystallization Process ◽  
Metal Free ◽  
Mild Conditions ◽  
Wide Range

An efficient and transition-metal-free protocol for the synthesis of (Z)-N-arylnitrones from the direct coupling of N-nosylhydrazones with nitrosoarenes under mild conditions is described. The protocol is compatible with a wide range of functional groups placed on both the reagents and provided the corresponding nitrones in good to excellent yields by simple recrystallization process. The use of these 1,3-dipoles for the synthesis of substituted indoles is elaborated for 2,3-diphenyl-1H-indole.

Facile Protocols towards C2-Arylated Benzoxazoles using Fe(III)-Catalyzed C(sp 2-H) Functionalization and Metal-Free Domino Approach

Synlett ◽  
2018 ◽  
Vol 29 (11) ◽  
pp. 1469-1478 ◽  
Author(s):  
Chandi Malakar ◽  
Nagaraju Vodnala ◽  
Raghuram Gujjarappa ◽  
Arup Kabi ◽  
Mohan Kumar ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Drug Discovery ◽  
Precious Metals ◽  
Boronic Acids ◽  
The Other ◽  
Metal Free ◽  
Discovery Research ◽  
Drug Discovery Research ◽  
Wide Range ◽  
High Yields

Considering their growing attention in the field of medicinal chemistry and drug-discovery research, the facile and convenient approaches towards the preparation of 2-aryl benzoxazole derivatives have been described. The transformation is accomplished by using Fe(III)-catalyzed C–H activation of benzoxazoles with boronic acids to obtain a wide range of C2-arylated benzoxazoles in high yields. The developed method excludes the formation of self-coupling compounds as side products. On the other hand, the synthesis of the products is also achieved via a metal-free domino protocol by the reaction between 1-nitroso-2-naphthol and acetophenones using catalytic amounts of CBr4 in the presence of Cs2CO3 as base. The devised tandem method avoids the use of pre-activated α-haloketones as substrates. Due to their immense impact in marketed drugs and molecules under clinical trial, the described method can be a powerful tool for their synthesis which ­restricts the use of precious metals as catalyst.

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