452094-13-2Relevant academic research and scientific papers
Synthesis of (Thio)Furan-Fused Phospholes via Phosphonation Cyclization and a Base-Promoted Phospha-Friedel-Crafts Reaction
Chen, Siyu,Ding, Haixin,Hua, Yuhui,Huang, Haiyang,Li, Chenchen,Liu, Fen,Song, Xian-Rong,Xiao, Qiang,Yuan, Chengxiong
, (2022/02/07)
Herein, we developed a novel strategy for synthesizing ladder (thio)furan-fused phospholes via intermolecular phosphonation cyclization and a base-promoted phospha-Friedel-Crafts reaction under mild conditions. The starting substrates are readily available phosphinic acids and easy-to-handle alkynes. The details of the reaction mechanism were further rationalized using theoretical calculations. This protocol can be widely applied to synthesize furan- and thiofuran-fused phospholes as well as the corresponding large π-extended derivatives, which are of great interest in the domain of organic functional materials.
Synthesis of diarylalkanes through an intramolecular/intermolecular addition sequence by auto-tandem catalysis with strong Br?nsted base
Kondoh, Azusa,Ma, Chaoyan,Terada, Masahiro
supporting information, p. 10894 - 10897 (2020/10/02)
An auto-tandem catalysis with a strong Br?nsted base enabled the synthesis of diarylalkanes containing a benzofuran moiety. Potassiumtert-butoxide efficiently catalyzed both the intramolecular cyclization of less acidicortho-alkynylaryl benzyl ethers and the following intermolecular addition of diarylmethanes to styrenes, demonstrating the high potential of the catalysis in organic synthesis.
Iridium-Catalyzed Intramolecular Methoxy C?H Addition to Carbon–Carbon Triple Bonds: Direct Synthesis of 3-Substituted Benzofurans from o-Methoxyphenylalkynes
Torigoe, Takeru,Ohmura, Toshimichi,Suginome, Michinori
, p. 10415 - 10419 (2016/07/21)
Catalytic hydroalkylation of an alkyne with methyl ether was accomplished. Intramolecular addition of the C?H bond of a methoxy group in 1-methoxy-2-(arylethynyl)benzenes across a carbon–carbon triple bond took place efficiently either in toluene at 110 °C or in p-xylene at 135 °C in the presence of an iridium catalyst. The initial 5-exo cyclization products underwent double-bond migration during the reaction to give 3-(arylmethyl)benzofurans in high yields.
α-Lithiated Aryl Benzyl Ethers: Inhibition of [1,2]-Wittig Rearrangement and Application to the Synthesis of Benzo[b]furan Derivatives
Velasco, Rocío,Feberero, Claudia,Sanz, Roberto
, p. 4416 - 4419 (2015/09/28)
The use of t-BuLi at low temperature selectively leads to α-lithiation of benzyl phenyl ether generating a stable organolithium, which can be efficiently trapped with a variety of selected electrophiles prior to suffering the expected [1,2]-Wittig rearrangement. In the case of (o-alkynyl)phenyl benzyl ethers, the intermediate α-aryloxyorganolithium undergoes an unexpected anti intramolecular carbolithiation reaction leading to functionalized benzo[b]furan derivatives.
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.
