Reactions concerned in Tertiary Amine N-Oxides. XII. The Synthesis of Asymmetric Compounds containing the Ferroin or Cuproin Group

Disulfide-Functionalized 3-, 4-, 5-, and 6-Substituted 2,2‘-Bipyridines and Their Ruthenium Complexes

“…b Three mole % of (PPh 3 ) 2 PdCl 2 used. c Reference 8. d Only the ethyl esters are known 2 The Syntheses of 6-, 5-, and 4-(Hydroxymethyl)-2,2‘-bipyridines ( 2a , b , and c ) from Methyl 2,2‘-Bipyridinecarboxylates ( 1a , b , and c ) and LiAlH 4 product no.yield, %IR (film), ν cm -1 1 H NMR (CDCl 3 ), δ 2a 86 3424 (br), 3046, 2930, 1582, 1430 8.57 (d, 1H), 8.32−8.21 (m, 2H), 8.05 (d, 1H), 7.72 (m, 2H), 7.21 (m, 1H), 4.60 (s, 2H) 2b a 92 3619, 2941, 1590, 1555, 1461, 1017, 926 8.64 (dq, 1H), 8.56 (d, 1H), 8.32−8.26 (m, 2H), 7.84−7.7 (m, 2H), 7.3 (s, 1H), 4.72 (2H) 2c 58 3323, 3022, 2970, 1587, 1559, 1403, 1226, 1049 8.53 (br d, 1H), 8.45 (d, 1H), 8.19 (m, 2H), 7.7 (br t, 1H), 7.2 (m, 2H), 4.65 (s, 2H) a Reference 16. 3 The Syntheses of Di[(2,2‘-bipyridin-6-, 5-, and 4-yl)methyl] 3,3‘-Dithiodipropanoates ( 3a , b , and c ) from 6-, 5-, and 4-(Hydroxymethyl)-2,2‘-bipyridines ( 2a , b , and c ) and 3,3-Dithiodipropanoic Acid product no.mp, °Cyield, % IR (film), ν cm -1 1 H NMR (CDCl 3 ), δAnal.…”

Functionalized 2,2‘-Bipyridines and 2,2‘:6‘,2‘ ‘-Terpyridines via Stille-Type Cross-Coupling Procedures

“…In particular, the unsymmetrically disubstituted methylbipyridines are not as common. The 4,6‘- and the 4,5‘-dimethyl-2,2‘-bipyridines have been reported previously only as byproducts of the reaction of pyridine N -oxides with pyridine derivatives. , Starting from the cheap aminopicolines 1a − c , the corresponding bromopicolines 2a − c can be obtained in hundred gram quantities by a simple diazotation/bromination sequence (Scheme ). , The bromopicolines can be utilized on one hand as one coupling agent for the Stille coupling and on the other hand for the further conversion to the 2-tributylstannylpyridines 3a − c , which then act as the second coupling partner. The stannylation of the bromo compounds via n -butyllithium and the following transmetalation step can be performed nearly quantitative in the case of the 5- and 6-methyl-2-tributylstannylpyridine 3a and 3b .…”

“…The 4,6′-and the 4,5′-dimethyl-2,2′-bipyridines have been reported previously only as byproducts of the reaction of pyridine N-oxides with pyridine derivatives. 22,23 Starting from the cheap aminopicolines 1a-c, the corresponding bromopicolines 2a-c can be obtained in hundred gram quantities by a simple diazotation/bromination sequence (Scheme 1). 24,25 The bromopicolines can be utilized on one hand as one coupling agent for the Stille coupling and on the other hand for the further conversion to the 2-tributylstannylpyridines 3a-c, which then act as the second coupling partner.…”

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

“…In contrast to such monosubstituted methyl-bipyridines and symmetrically disubstitued methyl-2,2‘-bipyridines, the unsymmetrically disubstituted methyl-bipyridines are not as common. 5,6‘-Dimethyl-2,2‘-bipyridine has not yet been synthesized and 4,6‘- and the 4,5‘-dimethyl-2,2‘-bipyridines are reported only as byproducts of the reaction of pyridine- N -oxides with pyridine derivatives 18a. However, such methyl-bipyridines can be used very efficiently as precursors for halomethyl-bipyridines, which can be synthesized via classical NBS halogenation 19 and in very high yields via a new “TMS route” .…”