51738-10-4Relevant academic research and scientific papers
A Radical-Initiated Fragmentary Rearrangement Cascade of Ene-Ynamides to [1,2]-Annulated Indoles via Site-Selective Cyclization
Li, Sifan,Wang, Yu,Wu, Zibo,Shi, Weiliang,Lei, Yibo,Davies, Paul W.,Shu, Wei
, p. 7209 - 7214 (2021/09/14)
Straightforward access to [1,2]-annulated indoles, key substructures in natural products, is highly desirable yet challenging. Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides is presented, providing a rapid access into [1,2]-annulated indoles by an intermolecular radical addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N cyclization sequence. DFT calculations support oxidation of N-centered radical species to cations prior to the C-N bond formation, followed by an unusual aza-Nazarov cyclization.
Hydroxamic acid derivative, and preparation method and application thereof
-
, (2019/12/25)
The invention relates to the technical field of enzyme inhibitors, and especially relates to a hydroxamic acid derivative, and a preparation method and an application thereof. A hydroxamic acid groupin the hydroxamic acid derivative is chelated with activ
Pd-Catalyzed decarboxylative alkynylation of alkynyl carboxylic acids with arylsulfonyl hydrazides via a desulfinative process
Chang, Sheng,Liu, Ying,Yin, Shu Zhu,Dong, Lin Lin,Wang, Jian Feng
supporting information, p. 5357 - 5362 (2019/04/04)
In the presence of a Pd(ii)/P-ligand catalytic system, decarboxylative alkynylation of alkynyl carboxylic acids and arylsulfonyl hydrazides by desulfinative coupling could provide aryl alkynes in satisfactory yields by either judiciously selecting palladium catalysts or modulating phosphine ligands under mild conditions. The reported coupling reactions are very practical as they do not require the protection of inert gas or oxygen and are tolerant to many functional groups.
Visible Light-Catalyzed Decarboxylative Alkynylation of Arenediazonium Salts with Alkynyl Carboxylic Acids: Direct Access to Aryl Alkynes by Organic Photoredox Catalysis
Yang, Liangfeng,Li, Haifeng,Du, Yijun,Cheng, Kai,Qi, Chenze
, p. 5030 - 5041 (2019/11/03)
A convenient method mediated by photoredox catalysis is developed for the direct construction of aryl alkynes. Readily available aromatic diazonium salts have been utilized as the aryl radical source to couple alkynyl carboxylic acids to feature the decarboxylative arylation. A wide range of substrates are amenable to this protocol with broad functional group tolerance, and diversely-functionalized aryl alkynes could be synthesized under mild, neutral and transition metal-free reaction conditions using visible light irradiation. Alongside synthetic sustainability associated with the photocatalytic and transition metal-free operation, another key point of this method is that the organic dye catalyst acts as an excited-state reductant, thus establishing the quenching cycle for radical addition and decarboxylative elimination. (Figure presented.).
Na2S-mediated synthesis of terminal alkynes from: Gem -dibromoalkenes
Singh, Radhey M.,Nandini, Durgesh,Bharadwaj, Kishor Chandra,Gupta, Tanu,Singh, Raj Pal
supporting information, p. 9979 - 9982 (2017/12/26)
The Na2S-mediated facile synthesis of terminal alkynes from gem-dibromoalkenes, at 20/40 °C under open flask conditions has been developed. Various precursors derived from heteroaromatic/aromatic/aliphatic aldehydes were found compatible. The reaction is proposed to proceed through the Fritsch-Buttenberg-Wiechell (FBW) rearrangement involving the corresponding vinyl carbene. Using mild reaction conditions with inexpensive Na2S·9H2O under air atmosphere has significant advantages over earlier routes.
Microwave-Assisted Dibromoolefination of Aromatic and Heteroaromatic Aldehydes and Ketones
Nauroozi, Djawed,Bruhn, Clemens,Fürmeier, Sven,Holzhauer, J?rn-Uwe,Faust, Rüdiger
supporting information, p. 615 - 619 (2016/04/19)
Microwave (MW) irradiation was successfully employed to convert aromatic and heteroaromatic aldehydes and ketones efficiently to the corresponding dibromoolefins. Exemplified by the successful dibromoolefination of traditionally inert pyridyl-flanked carbonyls, MW activation significantly broadens the scope of this valuable transformation, although some limitations especially with electron-rich aromatic ketone derivatives remain.
Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
Ma, Xiaoshen,Herzon, Seth B.
, p. 8673 - 8695 (2016/10/17)
Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
The Dual Role of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) in the Synthesis of Terminal Aryl- and Styryl-Acetylenes via Umpolung Reactivity
Morri, Ashok Kumar,Thummala, Yadagiri,Doddi, Venkata Ramana
supporting information, p. 4640 - 4643 (2015/09/28)
The dual role of the bicyclic amidine base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was demonstrated in a synthesis of terminal aryl- and styryl-acetylenes. Mechanistically, a tandem process involving elimination/Umpolung/protonation occurs in a single step to generate terminal aryl- and styryl-acetylenes from geminal dibromoalkenes. The key to the success of this transformation lies in the organobase-mediated generation of the acetylide from the 1-bromoalkynes at room temperature. The unique characteristics of DBU as an inherently safer reagent make it an attractive alternative to previous systems wherein required pyrophoric reagents and nonambient temperatures remain unsolved issues. The procedure does not work for the synthesis of alkyl-acetylenes.
Novel push-pull dendrons with high excited state dipole moments. Synthesis and theoretical analysis of unusual "branched electron distribution"
Guadarrama, Patricia,Terán, Gerardo,Ramos, Estrella,Gutiérrez, Jorge,Hernández, Madelyn
, p. 17 - 24 (2015/02/19)
The synthesis of novel highly delocalized push-pull dendrons is described. A modified protocol to conventional CC coupling reaction was used with moderate yields. The excited state dipole moments of synthesized dendrons were estimated by the solvatochromi
One-pot sequential alkynylation and cycloaddition: Regioselective construction and biological evaluation of novel benzoxazole-triazole derivatives
Srivastava, Ananya,Aggarwal, Leena,Jain, Nidhi
, p. 39 - 48 (2015/01/30)
Individually, benzoxazole and triazole moieties are of significant biological interest owing to their importance in drugs and pharmaceuticals. To assess their combined biological impact when woven into one molecule, we designed a novel, regioselective, multicomponent, one-pot (MCOP) approach for the construction of benzoxazole-linked triazoles. The synthesis has been achieved in two sequential steps involving copper-catalyzed alkynylation of benzoxazole followed by a 1,3-dipolar cycloaddition reaction. By combination of these two bioactive units into one core, a series of new benzoxazole-triazole scaffolds has been synthesized and subjected to in vitro antibacterial and anticancer evaluation. Tests against clinical isolates of Staphylococcus aureus and Escherichia coli showed potent Gram-negative activity for compounds 4{1,1,1}, 4{1,1,4}, and 4{1,2,1}. The cytotoxicity of the synthesized library was determined against three cancer cell lines: HeLa, SKBr3, and Hep G2. Compound 4{2,2,2} showed significant cytotoxicity against all the cell lines. These preliminary bioassay evaluations strongly suggest the promise and scope of these novel molecules as therapeutic agents in medical science.
