211491-23-5Relevant academic research and scientific papers
2-Substituted-3-allenyl-benzo[b]furans through the palladium-catalysed cyclization of propargylic o-(Alkynyl)phenyl ethers
Cacchi, Sandro,Fabrizi, Giancarlo,Moro, Leonardo
, p. 5101 - 5104 (1998)
The reaction of propargylic o-(alkynyl)phenyl ethers in the presence of Pd(PPh3)4 and K2C03 affords 2-substituted-3-allenylbenzo[b]furans in good yields. Depending on the nature of the starting alkyne, variable
Thermal [2 + 2]-cycloaddition between silylalkynes and allenylphenols followed by the nucleophilic addition of water: Metal-free and economical synthesis of arylcyclobutenals
Ohno, Shohei,Avena, Ramon Francisco,Aoyama, Hiroshi,Fujioka, Hiromichi,Arisawa, Mitsuhiro
, p. 1220 - 1228 (2020/03/11)
Herein, we report an unprecedented thermal [2 + 2]-cycloaddition between silylalkynes and allenylphenols to form an aromatizing cyclobutachromene intermediate, followed by the nucleophilic addition of water to yield functionalized arylcyclobutenals. This reaction is atom- and pot-economical because all the atoms contained in the starting material are retained in the final product, no other reactants are required, and it proceeds in one-pot.
Potassium tert-butoxide promoted annulation of 2-alkynylphenyl propargyl ethers: Selective synthesis of benzofuran and 12H-benzoannulene derivatives
Grimaldi, Tamiris B.,Back, Davi F.,Zeni, Gilson
, p. 11017 - 11031 (2013/11/19)
We present here our results on potassium tert-butoxide promoted annulation reactions of 2-alkynylphenyl propargyl ethers to give two different types of heterocycles: 3-benzyl-2-alkynylbenzofurans and 12H-benzoannulenbenzo[b]furans. A series of functionalized 2-alkynylphenyl propargyl ethers were efficiently cyclized by potassium tert-butoxide to the corresponding products. The optimized reaction conditions tolerated a large variety of functional groups, including electron-rich, electron-poor, and N-heterocyclic substrates. Selective product formation was obtained by controlling the solvent and temperature. When THF was used at room temperature, 3-benzyl-2-alkynylbenzofuran derivatives were exclusively obtained, while the use of DMF at 60 C gave selectively 12H-benzoannulen[b]benzofurans.
Et3N-promoted sequential reactions for the synthesis of 6H-benzo[c]chromenes
Chen, Wan-Li,Li, Jiao,Zhu, Ying-Hong,Hu, Wei,Mo, Wei-Min
experimental part, p. 16 - 25 (2012/03/26)
An interesting Et3N-promoted sequential reaction consisting of propargyl-allenyl isomerizations, intramolecular [4+2] cycloaddition and aromatization has been developed, providing a facile method for synthesis of 6H-benzo[c]chromenes under mild
