2876-46-2Relevant academic research and scientific papers
Metal-free benzannulation to synthesis of 2,3-disubstituted naphthalenes: Reaction of 2-(Phenylethynyl)benzaldehyde and alkynes by Br?nsted acid
Umeda, Rui,Ikeda, Naoki,Ikeshita, Masahiro,Sumino, Keita,Nishimura, Sota,Nishiyama, Yutaka
, p. 213 - 215 (2017/08/09)
Metal-free benzannulation reaction of 2-(phenylethynyl)- benzaldehyde and alkynes proceeded in the presence of Br?nsted acid under microwave irradiation to give the 2,3- disubstituted naphthalenes.
ZnCl2-catalyzed [4 + 2] benzannulation of 2-ethynylbenzaldehydes with alkynes: Selective synthesis of naphthalene derivatives
Fang, Xiao-Li,Tang, Ri-Yuan,Zhang, Xing-Guo,Zhong, Ping,Deng, Chen-Liang,Li, Jin-Heng
experimental part, p. 352 - 356 (2011/02/16)
Zn-catalyzed [4 + 2] benzannulation of 2-ethynylbenzaldehydes with alkynes is described for the selective synthesis of naphthalene derivatives. In the presence of ZnCl2, a variety of 2-ethynylbenzaldehydes underwent the [4 + 2] benzannulation reactions with alkynes to selectively afford the corresponding naphthalene derivatives in moderate to good yields.
Lewis acid-catalyzed [4 + 2] benzannulation between enynal units and enols or enol ethers: Novel synthetic tools for polysubstituted aromatic compounds including indole and benzofuran derivatives
Asao, Naoki,Aikawa, Haruo
, p. 5249 - 5253 (2007/10/03)
The reaction of enynals 1, including o-(alkynyl)benzaldehydes, and carbonyl compounds 2, such as aldehydes and ketones, in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 °C gave the functionalized aromatic compounds 3 in high yields. Similarly, the AuBr3-catalyzed reactions of 1 with acetal compounds 5 afforded the corresponding aromatic compounds 3 in good yields. On the other hand, when the reaction was carried out in the presence of a catalytic amount of Cu(NTf2)2 and 1 equiv of H2O in (CH2Cl)2 at 100 °C, the decarbonylated naphthalene products 4 were obtained selectively over 3. Benzofused heteroaromatic compounds, such as indole derivatives 13 and benzofuran derivatives 15, were also synthesized by using the present benzannulation methodology.
AuBr3-catalyzed [4 + 2] benzannulation between an enynal unit and enol
Asao, Naoki,Aikawa, Haruo,Yamamoto, Yoshinori
, p. 7458 - 7459 (2007/10/03)
The reaction of enynals 1, including o-alkynylbenzaldehydes, and carbonyl compounds 2 in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 °C gave the functionalized aromatic compounds 3 in high yields. The AuBr3-catalyzed formal [4 + 2] benzannulation proceeds most probably through the coordination of the triple bond of 1 to AuBr3, the formation of a pyrylium auric ate complex via the nucleophilic addition of the carbonyl oxygen atom, the reverse electron demand-type Diels-Alder addition of the enols, derived from 2, to the auric ate complex, and subsequent dehydration and bond rearrangement. Similarly, the AuBr3-catalyzed reactions of 1 with acetal compounds afforded the corresponding aromatic compounds in good yields. Copyright
