Results 111 to 120 of about 490 (165)

Visible Light-Mediated Spiroannulation of o-Alkynyl Acrylamides Using Excited-State Palladium Catalysis.

Journal of Organic Chemistry
A photoinduced, Pd-catalyzed spiroannulation of 1,7-enynes has been developed. This reaction employs simple alkyl halides as radical precursors to initiate a radical addition/cyclization cascade of o-alkynyl acrylamides, resulting in spiroannulated ...
Kirti Khanna, Ganesh Chandra Upreti, Parashuram Sharma, Shreya Sharma, Anand Singh   +4 more
semanticscholar   +1 more source

DMAP‐Catalyzed [4 + 3] Spiroannulation of Ninhydrin‐Derived MBH Carbonates with Acyclic Azadienes: Efficient Access to Multisubstituted Spiro[indanone‐azepine] Scaffolds

Asian Journal of Organic Chemistry
Indanedione‐containing spirocyclic derivatives are of significant interest in medicinal chemistry. However, spirofusion of indanediones with seven‐membered rings remains relatively unexplored.
Xiang‐Hong He, Xiao‐Ling Wu, Xin Zhang, Heping Li, Bo Han, Qian Zhao   +5 more
semanticscholar   +1 more source

Access to Succinimidyl Spirocyclobutenes via Spiroannulation of Bicyclo[1.1.0]Butanes and Azaoxyallyl Cations.

Chemistry - An Asian Journal
We herein disclose a base-mediated annulation reaction between azaoxyallyl cation and arylbicyclo[1.1.0]butane carboxylates (BCBs) to access succinimidyl spirocyclobutenes.
Aaron Taites, Subhadeep Hazra, Natish, Jaideep Saha   +3 more
semanticscholar   +1 more source

Enantioselective Synthesis of Ring-Fused Spiroannulated 1,2,3-Thiadiazole Derivatives

The Journal of Organic Chemistry, 2016
An organocatalytic enantioselective domino α-amination/oxidative coupling/cyclization of thioamides to azodicarboxylates catalyzed by an easily available organic catalyst has been developed. The key step, oxidative coupling, is smoothly fulfilled in air.
Xue-Mei, Zeng, Jian-Wu, Xie
openaire   +2 more sources

Acid-Catalyzed [4+1]-Dearomatization Spiroannulation of Hydroquinones and Naphthols

Synlett, 2023
AbstractAcid-catalyzed [4+1]-dearomatization spiroannulation reactions of electron-rich hydroquinone and naphthol derivatives were demonstrated as convenient methods to access spirocyclic cyclohexadienone derivatives. The Lewis acid Bi(OTf)3 exhibited the best catalytic performance when a 1,2-dialkynylbenzene was used as the electrophile for the ...
Zhi Li, Nan Ding
openaire   +1 more source

Mechanosynthesis of Pyrrole-2-carboxylic Acids via Copper-Catalyzed Spiroannulation/Ring-Opening Aromatization of 4-Arylidene Isoxazol-5-ones with Enamino Esters.

Organic Letters
An efficient and practical tandem reaction of 4-arylidene isoxazol-5-ones with enamino esters catalyzed by an inexpensive copper salt has been established in a ball mill.
Ming-Jun Li, Huimin Xiao, Peng Xu, Luan-Ting Wu, Si Chen, Ze Zhang, Hui Xu   +6 more
semanticscholar   +1 more source

Studies Directed to the Synthesis of New C‐5 Spiroannulated Julolidines.

ChemInform, 2002
AbstractFor Abstract see ChemInform Abstract in Full Text.
Alirio Palma, Javier Silva Agredo, Claudia Carrillo, Vladimir Kouznetsov, Elena Stashenko, Alı́ Bahsas, Juan Amaro-Luis   +6 more
openaire   +1 more source

Conia-Ene Cyclization of Pyrazolones with o-Alkynyl Aldehydes: A Strategic Shift from Classical Condensation to Spiroannulation.

Organic Letters
An unprecedented, atom-economic, and regioselective Conia-Ene cyclization from readily accessible pyrazolones and o-alkynyl aldehydes has been developed for the synthesis of spirocyclic frameworks.
Muskan, A. Verma
semanticscholar   +1 more source

Condition-Controlled Selective Synthesis of Spiroisoquinolinones or Spiroisoindolinones via CHA−Initiated Spiroannulation, Ring Opening and Ring Contraction

Organic Chemistry Frontiers
Presented herein is a condition-controlled selective synthesis of isoindole spiroisoquinolinone or isoindole spiroisoindolinone derivatives based on the cascade reactions of 3-phenylisoxazolone with diazo homophthalimide.
Yujing Xiao, Yuanshuang Xu, Shuya Zhang, Xinying Zhang, Xuesen Fan   +4 more
semanticscholar   +1 more source

An Eco-friendly Facile Synthesis of Perylene/Pyrene Framework Using Morita–Baylis–Hillman Adduct of Isatin with Anthracene via Twofold [3+3] Spiroannulation

Synlett : Accounts and Rapid Communications in Synthetic Organic Chemistry
An efficient and eco-friendly method for synthesizing a novel class of perylene- and pyrene-based frameworks was developed using Morita–Baylis–Hillman (MBH) adducts of isatin derivatives with anthracene, achieving good yields under metal-free conditions ...
S. Aruljothi, Sivaprakasam Sivaraman, Vadivel Vaithiyanathan   +2 more
semanticscholar   +1 more source