The synthesis of some 2-hydroxy-2(H)-3,3-diaryl- and 3-hydroxy-3(H)-2,2-diaryl-benzo[b]thiophens (4) and (7) respectively is described; by acidic treatment these compounds readily rearrange to 2,3-diaryl-benzo[b]thiophens (5) in almost quantitative yields.
Photopromoted Entry to Benzothiophenes, Benzoselenophenes, 3<i>H</i>-Indoles, Isocoumarins, Benzosultams, and (Thio)flavones by Gold-Catalyzed Arylative Heterocyclization of Alkynes
作者:Benito Alcaide、Pedro Almendros、Eduardo Busto、Fernando Herrera、Carlos Lázaro-Milla、Amparo Luna
DOI:10.1002/adsc.201700427
日期:2017.8.7
gold‐photoredox‐catalyzed reactions of heteroatom (N, S, Se, O) tethered alkynes with arenediazonium salts selectively proceeded to build vicinal diaryl‐substituted 2H‐benzo[e][1,2]thiazine 1,1‐dioxides (benzosultams), benzoselenophenes, benzothiophenes, 4H‐chromen‐4‐ones (flavones), 3H‐indoles, 1H‐isochromen‐1‐ones (isocoumarins), and 4H‐thiochromen‐4‐ones (thioflavones). Moreover, the utility of functionalized
dibenzothiophenes, undergo nucleophilic aromatic substitution with anilines intermolecularly and then intramolecularly to yield the corresponding carbazoles in a single operation. The “aromaticmetamorphosis” of dibenzothiophenes into carbazoles does not require any heavy metals. This strategy is also applicable to the synthesis of indoles. Since electron‐deficient thiaarene dioxides exhibit interesting reactivity
通过母体二苯并噻吩的氧化容易制备的二苯并噻吩二氧化物在一次操作中在分子内然后在分子内经历苯胺的亲核芳香取代,然后生成分子内相应的咔唑。二苯并噻吩向咔唑的“芳香变形”不需要任何重金属。该策略也适用于吲哚的合成。由于缺电子的硫杂芳烃二氧化物表现出有趣的反应性,而相应的富电子氮杂芳烃则未观察到,因此,二氧化硫杂ar特定反应与基于S N Ar的芳族变态反应的结合,使得无过渡金属的结构成为可能。难以制备咔唑。
Synthesis of Benzo[
<i>b</i>
]thiophenes through Rhodium‐Catalyzed Three‐Component Reaction using Elemental Sulfur
A benzo[b]thiophene synthesis by Rh‐catalyzedthree‐component coupling reaction of arylboronic acids, alkynes, and elemental sulfur (S8) is developed. A notable feature of this protocol is that the thienannulation (thiophene annulation) proceeds with high regioselectivity via the sequential alkyne insertion, C−H activation, and then sulfur atom transfer to the metallacycle intermediate. In a similar
开发了通过Rh催化的芳基硼酸,炔烃和元素硫(S 8)的三组分偶联反应合成苯并[ b ]噻吩。该协议的一个显着特征是,噻吩环化(噻吩环化)通过顺序的炔烃插入,CH活化以及随后的硫原子转移至金属环中间体而以高区域选择性进行。可以类似的方式,由母体联芳基硼酸和S 8合成二苯并噻吩。
Selective Palladium-Catalysedipso Arylation of α,α-Disubstituted Benzo[b]thien-2-ylmethanols with Aryl Bromides using PCy3 as Ligand
作者:A. Beatrix Bíró、András Kotschy
DOI:10.1002/ejoc.200600929
日期:2007.3
α,α-Diphenylbenzo[b]thien-2-ylmethanol was treated with a series of arylbromides in the presence of palladium(II) acetate and tricyclohexylphosphane to give the appropriate 2-aryl-benzo[b]thiophenes in good to excellent yield with concomitant formation of benzophenone. The reaction wassuccessfully extended to α,α-diphenylbenzo[b]thien-3-ylmethanol, although in certain cases the transformation was