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Bipyridine and related compounds are starting materials or precursors for a variety of valuable substances such as biologically active molecules, ligands for catalysts, photosensitizers, viologens, and supramolecular architectures. Thus, it is important to classify their synthesis methods and understand their characteristics. Representative examples include methods using homo and heterocoupling of pyridine derivatives in the presence of a catalyst. Because bipyridine compounds strongly coordinate with metal centers, a decrease in catalytic activity and yield is often observed in the reaction system. To address this issue, this review provides insights into advances over the last ~30 years in bipyridine synthesis using metal complexes under both homogeneous and heterogeneous conditions. Moreover, strategies for bipyridine synthesis involving sulfur and phosphorous compounds are examined. These alternative pathways offer promising avenues for overcoming the challenges associated with traditional catalysis methods, providing a more comprehensive understanding of the synthesis landscape. [ABSTRACT FROM AUTHOR]

Bipyridine and related compounds are starting materials or precursors for a variety of valuable substances such as biologically active molecules, ligands for catalysts, photosensitizers, viologens, and supramolecular architectures. Thus, it is important to classify their synthesis methods and understand their characteristics. Representative examples include methods using homo and heterocoupling of pyridine derivatives in the presence of a catalyst. Because bipyridine compounds strongly coordinate with metal centers, a decrease in catalytic activity and yield is often observed in the reaction system. To address this issue, this review provides insights into advances over the last ~30 years in bipyridine synthesis using metal complexes under both homogeneous and heterogeneous conditions. Moreover, strategies for bipyridine synthesis involving sulfur and phosphorous compounds are examined. These alternative pathways offer promising avenues for overcoming the challenges associated with traditional catalysis methods, providing a more comprehensive understanding of the synthesis landscape.

3-iodopropionic acid (3-IPA) can be efficiently synthesized from the glycerol derivative glyceric acid (GA), which is a potential biomaterial-based platform molecule. In this report, ethyl 3-iodopropionate was rapidly dimerized to diethyl adipate in a microwave reactor using NiCl2·6H2O as a catalyst, co-catalyzed by Mn and the 1, 10-Phenanthroline monohydrate ligand. Under the optimum reaction conditions, diethyl adipate can be obtained with 84% yield at 90 °C in just 5 min. Diethyl adipate was hydrolyzed to obtain the adipic acid (AA) in 89% yield with an acid catalyst. AA is an important chemical and a monomer for producing a wide range of high-performance polymeric substances. This rapid coupling method is also applicable to other alkyl halides. [ABSTRACT FROM AUTHOR]

Abstract: Sonochemically enhanced Wurtz coupling using lithium metal has been investigated for a number of isomeric alkyl bromides under a variety conditions. The products result from direct coupling of short lived radicals formed at the metal surface rather than the secondary radicals which can be formed during coupling of aromatic halides and thus give rise to a single major product. Coupling has been extended to dibrominated aryl and alkyl compounds as well as showing that aryl–alkyl coupling is possible. Dibrominated alkyls were found to give low molecular weight oligomers although no reaction occurred for 1,2-isomers. The growth of oligomers in THF may be solubility limited. A simple model is proposed to explain these findings. [Copyright &y& Elsevier]

Two perfluorinated potentially polymerizable dichlorostannane monomers, RSnCl, [R = ( p-CFCH), ((3,5-CF)CH)] have been prepared in good yield by the comproportionation reactions of the corresponding tetrarylstannanes ( 1, 2) and tin tetrachloride. The chlorinated monomers 5 and 6 were characterized by X-ray crystallography, H, C, and Sn NMR spectroscopy. The Wurtz coupling behaviour of these dichloromonomers with Na metal in the presence of 15-Crown-5 was also investigated and moderate to very high molecular weight polystannanes 8 and 9 where detected by GPC (M = 1.1–1.5 × 10 Da). The introduction of perfluorinated, strongly electron-withdrawing substituents on the phenyl rings of the resulting polystannanes causes a considerable blue-shift (>50 nm) of the σ–σ* λ transition relative to that of polydiphenylstannane. The perfluorinated groups were designed to impart improved moisture stability relative to non-fluorinated analogues. The new polymers 8 and 9 were found to be extremely light sensitive and readily degraded to oligomeric species upon exposure to ambient light. [ABSTRACT FROM AUTHOR]

Abstract: Poly((i-butyl-n-decylsilane) x -b-(methyl-3,3,3-trifluoropropylsilane)1−x ) (PSi3) was prepared using a simultaneous block copolymerization with a conventional Wurtz-type condensation reaction. The block-like polysilane copolymer showed high selectivity and sensitivity toward fluoride ion (F−) even in the coexistence of the halide ions (Cl−, Br−, and I−), and high solubility to common organic solvents with the dielectric constants (ɛ′) between 1.88 (n-hexane) and 9.04 (benzotrifluoride). Such unique characteristics were derived from poly(methyl-3,3,3-trifluoropropylsilane) (PSi1) and poly(i-butyl-n-decylsilane) (PSi2) unit in the copolymer, respectively. In addition, sensitivity to F− and solubility in organic solvents were successfully optimized by adjusting the composition ratio between PSi1 and PSi2 unit. [Copyright &y& Elsevier]

The polysilanes [RMe2Si(CH2)x(Me)Si]n [x = 2, 3; R = 2‐Fu (1, 2), 5‐Me‐2‐Fu (3, 4)] bearing furyl‐substituted carbosilyl side chains have been synthesized by dehalocondensation reaction (Wurtz coupling) of the corresponding carbosilanes using sodium dispersion in refluxing toluene. On the other hand, analogous polysilanes with appended thienyl groups [x = 2, 3; R = 2‐Th (5, 6), 4‐Me‐2‐Th (7, 8)] are only accessible by the reaction of the corresponding carbosilane precursors under mild Wurtz coupling conditions (THF, RT). These polysilanes reveal monomodal molecular weight distribution with Mw/PDI = 3.3–5.4 × 104/1.22–1.47 (1–4) and 9.1–14.4 × 104/1.45–1.61 (5–8) and are characterized by FT‐IR, multinuclear (1H, 13C{1H}, 29Si{1H}) NMR, and UV/PL spectral studies as well as thermogravimetric analysis (TGA). Preliminary studies on the reactivity of polysilane 2 with palladium acetate (toluene, RT) reveal the formation of spherical palladium nanoparticles of size 8.2 ± 0.6 nm, which remain stable in solution for several weeks. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7816–7826, 2008 [ABSTRACT FROM AUTHOR]

Wurtz coupling of dibutylaminotrimethyl-1,2-dichlorodisilane 1, which is readily available from by-products in the industrially operated direct synthesis of chloromethylsilanes, afforded polymer 2, a partially networked (branched) structure, where the degree of cross-linking depends on the polymerization conditions such as the temperature. Polymer 2, which has a network structure, shows an absorption maximum at about 360 nm that is approximately 30 nm red-shifted relative to the absorption maximum of poly(dialkylsilane)s. In the emission spectra, 2 exhibits a broad emission at 440 and 400 nm, which is ascribed to the network (or branching) silicon units and the linear silicon chains, respectively. The unusual photophysical properties presumably arise from the amino groups on silicon as well as the network structure. [ABSTRACT FROM AUTHOR]

Abstract: A number of copolysilanes, (R, R′=Me, Et or Ph; R1 =Me (1–3); Ph (4–6)) bearing carbosilyl side chains have been synthesized by Wurtz coupling method and characterized by GPC, multinuclear (1H, 13C{1H}, 29Si{1H}) NMR and UV spectral studies. A detailed study of 29Si{1H} NMR spectra suggests that the copolysilanes 1–3 are comprised of segregated runs of PhMeSi and RMeSi (R=carbosilyl) units while 4–6 possess many different configurational and conformational environments. The UV spectra of these copolymers reveal a distinct absorption (λ max) at 312–352nm due to σ–σ∗ transition and show a strong dependence on the polymer composition as well as nature of the appended sila substituents. [Copyright &y& Elsevier]

The use of the Barbier-Grignard reaction, where premixed allyl bromide and the carbonyl compound are added to magnesium in ether, is reported for the synthesis of homoallylic alcohols. This reaction provides good to excellent yields of most homoallylic alcohols with minimal formation of Wurtz coupling products. [ABSTRACT FROM AUTHOR]

A [10,10]paracyclophane, 5,5,6,6,21,21,22,22-octamethyl-5,6,21,22-tetragerma[10.10]paracyclophane (4a), with two &z.sbnd;R1R2GeGeR1R2&z.sbnd; moieties in the center of two bridges, was prepared. An attempt to synthesize cyclophanes, 4b (R1=Me; R2=Ph) and 4c (R1=R2=Ph) was also made. The products were not analytically pure even after strenuous purification procedure to indicate that a double Wurtz coupling reaction is extremely difficult and necessarily accompanied by formation of polymeric by-products. [Copyright &y& Elsevier]

Terminally functionized terpenoids of the bis-norfarnesane series, stereoisomeric with respect to the central double bond, were synthesized on the basis of 1,4-butynediol. Their electrophilic cyclization under the action of the complex Hg(OSOCF)·PhNMe led to a moderate yield of a mixture of monocyclic olefins. [ABSTRACT FROM AUTHOR]