Application of the Meerwein reaction of 1,4-benzoquinone to a metal-free synthesis of benzofuropyridine analogues

• Rashmi Singh,
• Tomas Horsten,
• Rashmi Prakash,
• Swapan Dey and
• Wim Dehaen

Beilstein J. Org. Chem. 2021, 17, 977–982, doi:10.3762/bjoc.17.79

• . Electrophilic substitution and further condensations give polycyclic systems, including oxazolo- and chromeno-fused analogues. Keywords: benzofuropyridines; benzoquinones; dibenzofurans; Meerwein reaction; metal-free synthesis; Introduction Dibenzofurans are important oxygen-containing heterocycles present in

• cancer cell lines [12][13]. Fluoroquinophenoxazines 2 have been used as telomerase inhibitors in anticancer research [14]. Furthermore, benzofuroisoindoles 3 were part of a kinase inhibitor study [15]. Photobiologically active psoralene (linear furocoumarin) dibenzofurans 1 and angular furanocoumarin

• dibenzofurans 4 were also explored for the treatment of various skin diseases [16]. Furthermore, 2-substituted benzofurobenzofurans 5 with antitubercular activity have been reported [17]. Prado et al. reported the antimycobacterial activity of furo[3,2-f]chromene analogue 6 [18]. The aza analogues of

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• directing groups: In 2016, the Zhang and Fan group described the first phenolic moiety directed hydroxylation. Pd(OAc)2 catalyzed hydroxylation of [1,1’-biphenyl]-2-ols using TBHP as oxidant in acetonitrile (Scheme 45) [74]. The reaction predominantly afforded biphenols as product, rather than dibenzofurans

Rapid regio- and multi-coupling reactivity of 2,3-dibromobenzofurans with atom-economic triarylbismuths under palladium catalysis

• Maddali L. N. Rao,
• Jalindar B. Talode and
• Venneti N. Murty

Beilstein J. Org. Chem. 2016, 12, 2065–2076, doi:10.3762/bjoc.12.195

• the synthesis of 2,3-dialkenylbenzofurans and functionalized dibenzofurans with domino “twofold Heck/6π-electrocyclization” of 2,3-di- and 2,3,5-tribromobenzofuran substrates [34]. In this regard, the cross-coupling studies of triarylbismuth reagents in regioselective studies with functionalized

Phytoalexins of the Pyrinae: Biphenyls and dibenzofurans

• Cornelia Chizzali and
• Ludger Beerhues

Beilstein J. Org. Chem. 2012, 8, 613–620, doi:10.3762/bjoc.8.68

• Cornelia Chizzali Ludger Beerhues Institut für Pharmazeutische Biologie, Technische Universität Braunschweig, Mendelssohnstr. 1, 38106 Braunschweig, Germany 10.3762/bjoc.8.68 Abstract Biphenyls and dibenzofurans are the phytoalexins of the Pyrinae, a subtribe of the plant family Rosaceae. The

• Pyrinae correspond to the long-recognized Maloideae. Economically valuable species of the Pyrinae are apples and pears. Biphenyls and dibenzofurans are formed de novo in response to infection by bacterial and fungal pathogens. The inducible defense compounds were also produced in cell suspension cultures

• after treatment with biotic and abiotic elicitors. The antimicrobial activity of the phytoalexins was demonstrated. To date, 10 biphenyls and 17 dibenzofurans were isolated from 14 of the 30 Pyrinae genera. The most widely distributed compounds are the biphenyl aucuparin and the dibenzofuran γ