Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• [17]. Also, M2CO3-catalyzed (M = K or Cs) addition of phenols to bromoacetylenes produced bromovinyl phenyl ethers, which were converted into 4H-chromen-4-ones, benzo[b]furans, etc. [18][19][20][21]. The latter reaction attracted our attention and prompted us to explore the interaction of phenols and

• reductive coupling of acid halides with ketones [36][37] and acetolyses of α-phenoxy-α-diazoketones [38] were also employed. Recently, F. P. Cossío et al. [39] have described a method for the preparation of benzo[b]furans by thermal heating of a dispersion of α-phenoxyketones in Al2O3. We involved the

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• behaves as a terminal oxidant to form α-aminoalkyl radicals, whereas the formation of an Fe-peroxo species in the catalytic cycle was confirmed using a combination of EPR and ESI mass spectrometry experiments (Scheme 31D). One-pot processes for the synthesis of benzo[b]furans from aryl- or alkylketones

Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction

• Vaida Milišiūnaitė,
• Rūta Paulavičiūtė,
• Eglė Arbačiauskienė,
• Vytas Martynaitis,
• Wolfgang Holzer and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2019, 15, 679–684, doi:10.3762/bjoc.15.62

• derivatives [15][16][17][18]. For example, Damera et al. reported an efficient synthesis of 2-substituted benzo[b]furans with good yields by the base-promoted cyclization of easily accessible 2-alkynylphenols [19]. Recently, 2-arylbenzo[b]furans were conveniently synthesized by the one-pot tandem Hiyama

• previously successfully employed for the preparation of benzo[b]furans by the cyclization of o-alkynylphenols [19]. Unfortunately, no addition of the hydroxy group across the carbon–carbon triple bond was observed even after heating the reaction mixture under analogous reaction conditions for 24 hours (Table

Synthesis of novel 13α-estrone derivatives by Sonogashira coupling as potential 17β-HSD1 inhibitors

• Ildikó Bacsa,
• Rebeka Jójárt,
• János Wölfling,
• Gyula Schneider,
• Bianka Edina Herman,
• Mihály Szécsi and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2017, 13, 1303–1309, doi:10.3762/bjoc.13.126

• -substituted counterpart 15, the olefinic protons are shown as doublets with a large coupling constant of 12.2 Hz, which refers to their trans arrangement. Under the conditions used for the partial saturation, the ethynyl derivatives bearing a phenolic OH group (8c, 10c) furnished benzo[b]furans 12 and 14

Copper-promoted hydration and annulation of 2-fluorophenylacetylene derivatives: from alkynes to benzo[b]furans and benzo[b]thiophenes

• Yibiao Li,
• Liang Cheng,
• Xiaohang Liu,
• Bin Li and
• Ning Sun

Beilstein J. Org. Chem. 2014, 10, 2886–2891, doi:10.3762/bjoc.10.305

• established methods for the synthesis of benzo[b]furan and benzo[b]thiophene derivatives, the development of more convenient methods is of significant importance [9][10][11][12][13][14]. Commonly, the preparation of 2-substituted benzo[b]furans involves the usage of 2-halophenols as reaction precursors

• eliminated these problems to a large extent [25][26][27][28][29]. Nevertheless, the direct synthesis of benzo[b]furans from 2-haloalkynylbenzenes and the usage of 2-fluorophenylacetylene derivatives as substrates continues to represent a challenge. Indeed, Tsuji and co-workers have developed a transition

• metal-free process for the synthesis of benzo[b]furans from 2-fluorophenylacetylene derivatives. But the reaction requires conditions with a high reaction temperature for satisfactory yields. Unfortunately, only benzo[b]furans were obtained in this reaction [30]. Typically, the aryl halides used in the

Combined directed ortho-zincation and palladium-catalyzed strategies: Synthesis of 4,n-dimethoxy-substituted benzo[b]furans

• Verónica Guilarte,
• M. Pilar Castroviejo,
• Estela Álvarez and
• Roberto Sanz

Beilstein J. Org. Chem. 2011, 7, 1255–1260, doi:10.3762/bjoc.7.146

• , give rise to new and interesting dimethoxy-substituted benzo[b]furans. Keywords: benzo[b]furans; o-zincation; palladium; selectivity; Introduction The directed ortho-metallation (DoM) reaction has been widely used as a powerful and efficient method for regioselective functionalization of aromatic

• . However, their application to the synthesis of 4-substituted benzo[b]furans is especially challenging, because the meta-substituted starting materials tend to cyclize at the less hindered ortho-position, leading to the formation of 6-substituted heterocycles or a mixture of 6- and 4-substituted ones [32

• 2,3-difunctionalized phenol derivatives were applied to the synthesis of 4-functionalized benzo[b]furans [39], 4- or 7-alkoxyindoles [40], and 7-oxy-substituted benzo[b]thiophenes [41] by employing Pd-catalyzed cross-coupling reactions or halocyclization processes. Following our interest in the