Inclusion of Copper(I) into a Novel Bipyridine-Containing Tetraphosphadiplatinacyclophane

Abstract

The 5,5′‐bis(hydroxyalkyl)‐2,2′‐bipyridines 4a–c (Scheme 1) were prepared either in one step (4b, 4c) or in four steps (4a) starting with 5,5′‐dimethyl‐2,2′‐bipyridine in each case. Reaction of 4a–c with mesyl chloride afforded the bis(mesylates) [–C5H3N–(CH2)n–CH2–OSO2Me]2 5a–c [n = 1 (a), 2 (b), 3 (c)], which could easily be transformed into the diphosphanes 6a–c by reaction with LiPPh2. Treatment of 6c, 6b with Cl2Pt(NCPh)2 and (RC6H4)2Pt(COD) according to the high‐dilution method resulted in the formation of the tetraphosphadiplatinacyclophanes [–C5H3N–(CH2)4–PPh2PtCl2PPh2–(CH2)4–C5H3N–]2 (7c) and [–C5H3N–(CH2)3–PPh2Pt(C6H4R)2PPh2–(CH2)3–C5H3N–]2 (8b, 9b) (8b: R = H, 9b: R = tBu), respectively (Scheme 2). The molecular structures of 8b and 9b were elucidated by X‐ray structural analyses. The noncoordinated bipyridine moieties in 8b were employed to encapsulate copper(I) to give the host/guest complex 10b (Scheme 3), which was investigated by FAB‐MS, NMR spectroscopy, and cyclovoltammetry. 10b exhibited a quasi‐reversible oxidation at E1/2 = –0.31 V and an electrodeposition‐redissolution redox system at E1/2 = –0.79 V, owing to the formation of copper at the surface of the working electrode.

Reductive Couplings of 2-Halopyridines without External Ligand: Phosphine-Free Nickel-Catalyzed Synthesis of Symmetrical and Unsymmetrical 2,2′-Bipyridines

“…The product was isolated as a yellow solid in 78% yield (456 mg): mp = 215.9–217.8 °C, R f = 0.15 (petroleum ether/ethyl acetate = 3:1); IR (cm –1 , KBr) 2255; 1 H NMR (400 MHz, CDCl 3 ) δ 8.71 (s, 2H), 8.59 (d, J = 7.2 Hz, 2H), 7.95 (d, J = 7.9 Hz, 2H) 3.88 (s, 4H); 13 C NMR (100 MHz, CDCl 3 ) δ 155.4, 148.5, 136.6, 128.9, 121.4, 116.7, 29.7. Data was consistent with that reported in the literature …”

“…Data was consistent with that reported in the literature. 26 2,2′-Biquinoline (2r). The product was isolated as a white solid in 72% yield (461 mg): mp =193−195 °C; R f = 0.66 (petroleum ether/ ethyl acetate = 3:1); 1 H NMR (400 MHz, CDCl 3 ) δ 8.81 (d, J = 8.6 Hz, 2H), 8.28 (d, J = 8.6 Hz, 2H), 8.20 (d, J = 8.3 Hz, 2H), 7.83 (d, J = 8.1 Hz, 2H), 7.70 (t, J = 7.2 Hz, 2H), 7.52 (t, J = 7.4 Hz, 2H); 13 C NMR (100 MHz, CDCl 3 ) δ 150.0, 146.5, 136.8, 130.2, 127.7, 127.1, 125.8, 122.4, 121.6.…”

Flexible Building Blocks for Transition Metal Early−Late Chemistry. Synthesis of Heterobimetallic Tetranuclear Metallomacrocycles

“…The dinuclear compound [Pt(μ-SEt 2 )( p -tolyl) 2 ] 2 containing the labile diethyl sulfide ligands behaves as a source of unsaturated cis -PtR 2 fragments . Thus, the reaction with 4 molar equiv of HOCH 2 PPh 2 gave the compound cis -[Pt( p -tolyl) 2 (Ph 2 PCH 2 OH) 2 ] ( 6 ), which was isolated as a white solid in excellent yield.…”

Ligand-based backbone modifications for metal-chelating nucleic acids

“…2). 44 Subsequent addition of 4,49-dimethoxytrityl chloride yielded a trityl-Bpy-alcohol. 45 The phosphoramidite was then obtained by treatment with 2-cyanoethyl-N,N,N9,N9-tetraisopropylphosphoramidite (Fig.…”