Sonogashira reaction polymer reactions

Concerning other metals, Sonogashira coupling products have also been observed in the reaction of Ag(l)-carbenes [133] and Au(I)-supported carbenes [134] in low to moderate yields, but only under harsh conditions (more than 100°C). In this regard, NHC based catalysts for Sonogashira reactions have been supported on different materials that include clays [135], polymers [136] and peptides [137]. 

The suitability of the polymer-Hnker conjugate was examined for a variety of transformations, in particular Pd°-catalyzed reactions. For instance, the polymer-bound aryl iodide (63) was transformed quantitatively in a Heck reaction to a cinnamic acid ester (64) and to biphenyl (66) in a Suzuki reaction. It gave an alkyne (65) in a Sonogashira reaction (Scheme 10.12). 

The chemical structure of the polymers was confirmed by NMR and elemental analysis, and spectroscopically characterized in comparison with monodisperse low molecular weight model compounds. Scheme 5 outlines the approach to the model compounds. Model compounds 31-34 were synthesized by complexation of the ruthenium-free model ligands 29/30 with 3/4. The model ligands were synthesized in toluene/diisopropylamine, in a similar fashion as the polycondensation using Pd(PPh3)4 and Cul as catalyst (Sonogashira reaction) [34,47-49]. 

Jutand, A. Dual role of nucleophiles in palladium-catalyzed Heck, Stille, and Sonogashira reactions. Pure Appl. Chem. 2004, 76, 565-576. Li, C.-J., Slaven, W. T., John, V. T., Banerjee, S. Palladium catalyzed polymerization of aryl diiodides with acetylene gas in aqueous medium a novel synthesis of areneethynylene polymers and oligomers. Chem. Commun. 1997,1569-1570. 

SYNTHESIS OF 1 - [4-(2-PHEN YLETHYNYL)PHEN YL] ETHAN -1-ONE VIA SONOGASHIRA REACTION BY THE USE OF POLYMER-SUPPORTED PALLADACYCLE CATALYST... 

Yamamoto and Plenio introduced ferrocene units into PAEs and prepared redox-active PAEs 70 [107,109]. Yamamoto coupled l,l -diiodoferrocene to a diethynylarene by either a Sonogashira reaction or by utilizing alkynylgrignard reagents (Scheme 6.25). Plenio reported poly(l,3-ferrocenyleneethyny-lene)s 70d (Scheme 6.26) by a clever metallation strategy. Polymers 70 are structurally novel but have not found any applications. They might be useful as active layers in transistor-types due to their ease of oxidation. 

Scheme 9.10 Bis(pyrimidine)-based Pd-bound polymer 30 active in the Sonogashira reaction obtained by ring-opening metathesis polymerization (ROMP) of the norbornene 31 with the diene 32 and subsequent treatment with PdClj [110].

In 2007, Lee and coworkers reported the synthesis of a core-shell type polymer-supported (NHC)-Pd catalyst 28 (Figure 4.8), which was used to catalyze copper-free Sonogashira reactions under ambient atmosphere [39]. The... 

Pu and coworkers have synthesized and studied numerous binaphthyl-derived macrocycles and polymers. In 1998, they reported the synthesis of multipolar macrocycles 161-163 [58]. The macrocycles were produced as a separable mixture via a one-pot synthesis utilizing a Sonogashira cross-coupling reaction. 

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