The [2+2+2] cycloaddition (homo-Diels–Alder reaction) of N-substituted 1,2,4-triazoline-3,5-diones (TADs) with bicycloalkadienes produces strained heterocyclic compounds. A reaction the unsubstituted dienes occurs readily to produce only expected homo-Diels–Alder adducts. However, previous work in literature showed that attachment a single electron-withdrawing group diene system results formati...

2,4,6-Triisopropylstryrene was synthesized in a single step via the Witting Reaction from the corresponding aldehyde. The reaction of three styrene's derivatives, 2,6-dimethylstyrene, 2,4,6-trimethylstyrene, and 2,4,6- triisopropylstyrene with 4-methyl-l,2,4-triazoline-3,5-dion(M eTD) was investigated. These reactions are instantaneous at room temperature and lead to the formation of 2: 1 ...

Abstract: 3-(Trifluoromethyl)prop-2-yne 1-iminium triflate salts were generated from 3-trifloxy-3-(trifluoromethyl)prop-2-ene by triethylamine-assisted elimination of triflic acid and trapped in situ various cycloaddition reactions. These included Diels-Alder reactions with 1,3-dienes, [2+2] 1,4-diphenylbuta-1,3-diene, [3+2] organoazides. All these revealed the excellent dienophilic dipolarophi...

Microporous and mesoporous zincosilicates (e.g., CIT-6, VPI-8, Zn-MFI, and Zn-MCM-41) synthesized in the presence of alkali cations contain two broad types of Zn sites: one that is a dication analog of the monocation ion-exchangeable Al-site in aluminosilicates, while the other resembles isolated Zn sites on amorphous silica. The ratio of these sites varies, depending on the synthesis condition...

The present work describes synthetic concepts for the coupling of peptides to polyphenylene dendrimers (PPDs). Novel functionalized cyclopentadienones have been synthesized whose Diels-Alder cycloaddition with various core molecules leads to polyphenylene dendrimers possessing (protected) amino or carboxyl groups. In addition, the resulting functionalized molecules exhibit the characteristic sh...

New reactions and reagents that allow for multiple bond-forming events per synthetic operation are required to achieve structural complexity and thus value with step-, time-, cost-, and waste-economy. Here we report a new class of reagents that function like tetramethyleneethane (TME), allowing for back-to-back [4 + 2] cycloadditions, thereby amplifying the complexity-increasing benefits of Die...

Trifluoromethyl ynones derived from the 4th generation refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf) undergo rapid Diels-Alder cycloaddition reactions with furans in near quantitative yields. Subsequent deoxygenation of resulting oxabicyclic adducts leads to formation ortho-trifluoromethylbenzophenones generally good yields without need for purification by column chromatography. Complete ...

Stimuli-responsive polymers, with properties changing upon different environmental factor variations such as pH, light, mechanical stress or temperature, and polymeric nanoparticles have found many important applications in fields drug delivery, biosensing research. In this work, thermoresponsive that are able to react by Diels-Alder reaction (a diene-dienophile cycloaddition) were studied. The...

The combination of palladium catalysis and thermal cycloaddition is shown to transform tricyclic aziridines into complex, stereodefined tetracyclic products in a single step. This highly unusual cascade process involves diverted Tsuji–Trost sequence leading surprisingly facile intramolecular Diels–Alder reaction. starting materials are accessible on multigram scales from the photochemical rearr...