A cascade process for the synthesis of ortho-formyl allyl aryl ethers and 2H-chromen-2-ol derivatives from arynes via trapping of o-quinone methide with an activated alkene

2019 ◽  
Vol 17 (2) ◽  
pp. 333-346 ◽  
Author(s):  
Abhilash Sharma ◽  
Pranjal Gogoi

A transition-metal free synthetic strategy for the direct synthesis of ortho-formyl substituted allyl aryl ethers and 2H-chromen-2-ol derivatives via a cascade three-component coupling of arynes, activated alkene and N,N-dimethylformamide.

2020 ◽  
Vol 18 (14) ◽  
pp. 2727-2738 ◽  
Author(s):  
Hemanta Hazarika ◽  
Pranjal Gogoi

A transition-metal free synthetic strategy for the direct synthesis of ortho-methylthio allyl and vinyl ethers via cascade three-component coupling of aryne, activated alkene and DMSO.


2020 ◽  
Vol 44 (41) ◽  
pp. 17938-17953
Author(s):  
Abhilash Sharma ◽  
Pranjal Gogoi

A versatile transition-metal free synthetic strategy has been developed for the direct synthesis of 6-substituted indoloquinazolinones from 2-acyl-4-quinazolinones and aryne precursors. This cascade strategy proceeds via successive C–N and C–C bond formation in a single reaction vessel.


2019 ◽  
Vol 17 (26) ◽  
pp. 6450-6460 ◽  
Author(s):  
Kashmiri Neog ◽  
Dhiraj Dutta ◽  
Babulal Das ◽  
Pranjal Gogoi

A novel transition-metal free synthetic strategy for the direct synthesis of quaternary phosphonium triflates via insertion of aryne into phosphine oxide.


RSC Advances ◽  
2020 ◽  
Vol 10 (29) ◽  
pp. 17288-17292 ◽  
Author(s):  
Yiyong Zhao ◽  
Junjie Wei ◽  
Shuting Ge ◽  
Guofu Zhang ◽  
Chengrong Ding

Our gram-scale process uses abundant and inexpensive aldehydes, a clean nitrogen source, requires no additional carbon atoms, is transition-metal free, and features easy work-up and excellent functional group compatibility.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2225 ◽  
Author(s):  
Yongjun Bian ◽  
Xingyu Qu ◽  
Yongqiang Chen ◽  
Jun Li ◽  
Leng Liu

Thiourea as a sulfur atom transfer reagent was applied for the synthesis of aryl thioamides through a three-component coupling reaction with aryl aldehydes and N,N-dimethylformamide (DMF) or N,N-dimethylacetamide (DMAC). The reaction could tolerate various functional groups and gave moderate to good yields of desired products under the transition-metal-free condition.


2020 ◽  
Vol 16 ◽  
pp. 1740-1753 ◽  
Author(s):  
Dharmender Singh ◽  
Vipin Kumar ◽  
Virender Singh

A robust transition-metal-free strategy is presented to access novel β-carboline-tethered benzothiophenone derivatives from 1(3)-formyl-β-carbolines using elemental sulfur activated by Et3N/DMSO. This expeditious catalyst-free reaction proceeds through the formation of β-carboline-based 2-nitrochalcones followed by an incorporation of sulfur to generate multifunctional β-carboline-linked benzothiophenones in good to excellent yields. The synthetic strategy could also be extended towards the synthesis of β-carboline-linked benzothiophenes. Moreover, the afforded products emerged as promising fluorophores and displayed excellent light-emitting properties with quantum yields (ΦF) up to 47%.


Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2525-2538 ◽  
Author(s):  
James Bull ◽  
Renzo Luisi ◽  
Leonardo Degennaro

Sulfoximines are emerging as valuable new isosteres for use in medicinal chemistry, with the potential to modulate physicochemical properties. Recent developments in synthetic strategies have made the unprotected ‘free’ NH-sulfoximine group more readily available, facilitating further study. This account reviews approaches to NH-sulfoximines, with a focus on our contribution to the field. Starting from the development of catalytic strategies involving transition metals, more sustainable metal-free processes have been discovered. In particular, the use of hypervalent iodine reagents to mediate NH-transfer to sulfoxides is described, along with an assessment of the substrate scope. Furthermore, a one-pot strategy to convert sulfides directly into NH-sulfoximines is discussed, with N- and O-transfer occurring under the reaction conditions. Mechanistic evidence for the new procedures is included as well as relevant synthetic applications that further exemplify the potential of these approaches.1 Introduction2 Strategies to Form NH-Sulfoximines Involving Transition-Metal Catalysts3 Metal-Free Strategies to Prepare NH-Sulfoximines4 Mechanistic Evidence for the Direct Synthesis of NH-Sulfoximines from Sulfoxides and Sulfides5 Further Applications6 Conclusion


ChemInform ◽  
2015 ◽  
Vol 46 (24) ◽  
pp. no-no
Author(s):  
Luis F. R. Gomes ◽  
Luis F. Veiros ◽  
Nuno Maulide ◽  
Carlos A. M. Afonso

2021 ◽  
Author(s):  
Ritiele Heck ◽  
Thiago Anjos ◽  
Maira R Giehl ◽  
Ricardo F Schumacher ◽  
Benhur Godoi

Flavone and analogues represent an important class of biologically and pharmacologically active substances commonly found in the composition of diverse plants as part of the class of secondary metabolites. Herein, we have demonstrated an efficient and regioselective synthetic strategy for the preparation of functionalized flavones through sequential demethylation/6-endo-dig intramolecular cyclization of propyn-1-ones, using catalytic amounts of base in the presence of a thiol, by employing NMP as the solvent. The reactions proceeded smoothly under transition-metal-free and open to air conditions, furnishing the desired six-membered heterocycles in moderate to excellent yields, in short reaction time.


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