Tuneable access to indole, indolone, and cinnoline derivatives from a common 1,4-diketone Michael acceptor

• Dalel El-Marrouki,
• Sabrina Touchet,
• Abderrahmen Abdelli,
• Hédi M’Rabet,
• Mohamed Lotfi Efrit and
• Philippe C. Gros

Beilstein J. Org. Chem. 2020, 16, 1722–1731, doi:10.3762/bjoc.16.144

• ; indoles 6, indolones 7, and cinnolines 8, starting from common substrates 1,4-diketones 5 and primary amines. The protocols developed here used mild conditions, were functional-group tolerant, transition-metal-free, proceeded in moderate to good yield, and could therefore easily be used in medicinal

• conditions for the synthesis of the cinnolines 8. Supporting Information Supporting Information File 178: Experimental procedures, characterization data, and copies of the spectra of all compounds. Acknowledgements The authors would like to thank François Dupire (UMR 7053 – L2CM) and Fabien Lachaud (UMR

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• and a sila-Sonogashira coupling as the polycondensation technique. The fluorescence of the cinnoline-containing polymers in THF was highly sensitive to quenching by Pd2+ ions. Keywords: cinnolines; fluorescence quenching; Pd2+ detection; poly(arylene ethynylene)s; Sonogashira coupling; Introduction

• cinnoline 4a into the desired bis(trimethylsilylethynyl)cinnoline 5a (Table 2, entry 3). The optimized conditions were used in the synthesis of bis(trimethylsilylethynyl)cinnolines 5a,b, so that the starting materials for the synthesis of PAEs were obtained in good isolated yields (Table 2, entries 4 and 5

• -protected diethynylcinnolines to be used as a starting material instead of unstable terminal alkynes. It also avoids an extra synthetic step. When we tried polycondensation of bis(trimethylsilyl)cinnolines 5a,b with diiodoarene 9 in the presence of Pd(PPh3)4/CuI as a catalytic system and KF/MeOH as a

A facile synthesis of functionalized 7,8-diaza[5]helicenes through an oxidative ring-closure of 1,1’-binaphthalene-2,2’-diamines (BINAMs)

• Youhei Takeda,
• Masato Okazaki,
• Yoshiaki Maruoka and
• Satoshi Minakata

Beilstein J. Org. Chem. 2015, 11, 9–15, doi:10.3762/bjoc.11.2

• with a chlorine-containing oxidant (t-BuOCl) in the presence of a base (2,6-lutidine). In addition the basic physicochemical properties of newly synthesized compounds have been investigated. Keywords: aromatic amines; azahelicenes; cinnolines; halogen; oxidation; Introduction Helicenes, ortho-fused

• . Herein we present a facile, straightforward, and moderately functional-group-tolerant synthesis of 7,8-diaza[5]helicenes (benzo[f]naphtho[2,1-c]cinnolines) bearing functional substituents on the helical π-conjugated backbone through an oxidative ring-closure of BINAM derivatives (Scheme 2, the lower

Dimerisation, rhodium complex formation and rearrangements of N-heterocyclic carbenes of indazoles

• Zong Guan,
• Jan C. Namyslo,
• Martin H. H. Drafz,
• Martin Nieger and
• Andreas Schmidt

Beilstein J. Org. Chem. 2014, 10, 832–840, doi:10.3762/bjoc.10.79

• -amidate 5, and indazolium-3-thioamidate 6, respectively [23] (Scheme 2). Aliphatic ketones surprisingly give stable 1:1 adducts 7 [20][24]. α-Bromo acetophenones induce an unexpected ring enlargement to cinnolines 8 [25]. New ring systems such as 9 [25] and 10 [26] were prepared on treatment of indazol-3