356791-71-4Relevant academic research and scientific papers
A facile route to Aryl-substituted 1,10-phenanthrolines by means of Suzuki coupling reactions between substituted areneboronic acids and halogeno-1,10-phenanthrolines
Luening, Ulrich,Abbass, Michael,Fahrenkrug, Frank
, p. 3294 - 3303 (2007/10/03)
Twelve new mono- or diaryl-substituted 1,10-phenanthrolines (17 and 18) have been synthesized. The key step is a Suzuki coupling reaction between the substituted areneboronic acids 6, 11, and 15 and the mono- and dihalo-1,10-phenanthrolines 16. The syntheses of bis-ortho-substituted boronic acids 6, 11, and 15 from substituted arenes 5 or substituted bromoarenes 10 and 14 by lithiation and subsequent treatment with trimethyl borate is described. Not only 2,9-diiodo- (16c) but also 2,9-dichloro-1,10-phenanthroline (16b) can be used with good yields (65-92%) in the described Suzuki coupling. For the syntheses of unsymmetrically substituted 1,10-phenanthrolines 18b, 18i, and 18j, the use of 2- chloro-9-iodo-1,10-phenanthroline is not necessary; two different bis-ortho-substituted arene rings can be introduced stepwise in 46 to 64% total yield. ( Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
Concave 1,10-phenanthrolines by ring-closing metathesis
Luening, Ulrich,Fahrenkrug, Frank,Hagen, Martin
, p. 2161 - 2163 (2007/10/03)
Ring-closing metathesis using Grubbs' catalyst has been applied to the synthesis of the concave 1,10-phenanthrolines 5. Instead of a kinetically controlled double macrocyclization of the tetraphenol precursor 2 by two equivalents of ditosylates or diiodides, the new three step synthesis separates the alkylation of 2 from the macrocyclization. After the tetraalkylation of 2, the resulting tetraalkene 3 is cyclized by metathesis under thermodynamic control to give the bimacrocycles 4 in up to 92% yield. Hydrogenation of the alkene double bonds gave the bimacrocycles 5 in considerably improved overall yields (for instance for 5b from 19 to 79%).
