127049-50-7Relevant articles and documents
Synthesis of a Bolm's 2,2′-Bipyridine Ligand Analogue and Its Applications
Bedná?ová, Eva,Dra?ínsky, Martin,Malatinec, ?tefan,Císa?ová, Ivana,Lamaty, Frédéric,Kotora, Martin
, p. 2869 - 2878 (2018/08/17)
A new method of synthesis of an analogue of Bolm's 2,2′-bipyridine ligand based on the catalytic [2+2+2] cyclotrimerization of 1-halodiynes with nitriles was developed. Crucial step of the whole synthesis turned out to be homodimerization of a substituted 2-bromopyridine to the corresponding bipyridine, that was studied and optimized. The newly prepared bipyridine (S,S)-2 was then tested as a chiral ligand in metal-catalyzed enantioselective reactions. Out of the studied reactions the most promising results were obtained in epoxide ring opening (82% yield, 98% ee) and Mukaiyama aldol reaction (>96% yield, 99/1 dr, 92% ee). In the case of Mukaiyama-aldol reaction as well as in the Michael addition, novel ligand 2 proved its robustness compared to Bolm's ligand as it was less sensitive to the purity of used reagents. (Figure presented.).
Enantioselective Synthesis of Optically Active Pyridine Derivatives and C2-Symmetric 2,2'-Bipyridines
Bolm, Carsten,Ewald, Martina,Felder, Marcel,Schlingloff, Gunther
, p. 1169 - 1190 (2007/10/02)
Optically active pyridine derivatives 2, 15, 18, 19, 21, 26, and 27 are obtained by enantioselective reduction of the corresponding ketones 5, 7, 11-13, 24, and 25 using the chiral borane reagent chlorodiisopinocampherylborane .Nickel(0)-mediated coupling of bromopyridines 2, 15, and 31 gives C2-symmetric 2,2'-bipyridines (R,R)-32, (R,R)-33, and (S,S)-38, respectively, which form metal complexex with Co(II), Pd(II), Cu(I), and Ag(I).Aryl-substituted pyridines 26, and 39-41 are synthesized by palladium(0)-catalized cross coupling of 2 and 15 with boronic acids 42-44.Key Words: 2,2-Bipyridines / Pyridines, optically active / Chiral ligands / Asymmetric Synthesis / Catalysis, enantioselective