Stille-Type Cross-CouplingAn Efficient Way to Various Symmetrically and Unsymmetrically Substituted Methyl-Bipyridines:  Toward New ATRP Catalysts

Abstract

Various mono- and disubstituted 2,2'-bipyridines were synthesized in high yields and multigram scales utilizing Stille-type coupling procedures. The corresponding bromo-picoline and tributyltin-picoline building blocks were prepared from commercially available amino-picoline compounds. As first examples of metal complexes, 4,5'-dimethyl-2,2'-bipyridine was reacted with copper(II) and iron(II) ions and investigated as catalyst in ATRP.

Synthesis of 5-(2,2′-Bipyridinyl and 2,2′-Bipyridinediiumyl)-2′-Deoxyuridine Nucleosides: Precursors to Metallo-Dna Conjugates

“…A great variety of methods to prepare functionalized 2,2 0 -bipyridines have been described in the literature, [40,41,43,44,[46][47][48] and forming 6-bromo-2,2 0 -bipyridine (2, Sch. 1) was key to synthesizing 6-ethynylbipyridine (4).…”

Synthesis and Screening oft-Bu-CyMe4-BTBP, and Comparison with CyMe4-BTBP

“…The combined ether extracts were treated with sodium sulphate and concentrated using a rotary evaporator. Vacuum distillation of the resulting residue gave 4-tert-butyl-2,2'-bipyridine [25] (2) (19. The 4-tert-butyl-2,2'-bipyridine was dissolved in acetic acid (80 mL) and treated with an aqueous 35% (w/w) solution of hydrogen peroxide (50 mL).…”

Stabilization of the labile metal configuration in halfsandwich complexes [CpRh(PN)Hal]X

“…2-Methylpyridine (1a) is commercially available. 2-Menthoxy-6-methylpyridine (1b) was prepared by substitution of the bromo substituent in 2-bromo-6-methylpyridine [16] for the anion of L-(À)-menthol. 2-Diphenylphosphanylmethylpyridine (2a) is a known compound [17][18][19].…”

“…(1R,2S,5R)-Menthoxy-6-methylpyridine 1b L-(À)-Menthol (120 g, 768 mmol) was added to NaH (8.23 g, 343 mmol) under N 2 protection without a solvent and heated to 60°C. After the formation of H 2 had ceased, the temperature was raised to 90°C for 2 h. 2-Bromo-6-methylpyridine [16] (40 g, 232 mmol) was added and the mixture was kept at 90°C for 20 h. The excess of L-(À)-menthol was removed at 100°C/2 Torr. In a bulb-to-bulb distillation at 100°C/10 À3 Torr 1b was isolated and purified by chromatography Table 1 Crystallographic data for 3a, 3b, (S S )-5a, (L Ment ,R C )-6b and (R C )-6c…”