Suzuki-Miyaura coupling ligands

A variety of triazole-based monophosphines (ClickPhos) 141 have been prepared via efficient 1,3-dipolar cycloaddition of readily available azides and acetylenes and their palladium complexes provided excellent yields in the amination reactions and Suzuki-Miyaura coupling reactions of unactivated aryl chlorides <06JOC3928>. A novel P,N-type ligand family (ClickPhine) is easily accessible using the Cu(I)-catalyzed azide-alkyne cycloaddition reaction and was tested in palladium-catalyzed allylic alkylation reactions <06OL3227>. Novel chiral ligands, (S)-(+)-l-substituted aryl-4-(l-phenyl) ethylformamido-5-amino-1,2,3-triazoles 142,... 

Miura M (2004) Rational ligand design in constructing efficient catalyst systems for suzuki-miyaura coupling. Angew Chem Int Ed 43 2201-2203... 

When IBioxl2 HOTf was employed as the ligand precursor for the Suzuki-Miyaura coupling of sterically hindered aryl chlorides and aryl boronic acids, excellent to good yields were obtained in refluxing toluene for a variety of starting materials (Table 6). Notably, this work represents the first report of tetra-orf/zo-substitulcd biaryl compounds achieved from aryl chlorides [143]. 

A year later, Schmidt and Rahimit ° reported ligand 77 (Figure 8) to be highly efficient in Suzuki-Miyaura coupling. Combining 77 with Pd(OAc)2, this in situ generated... 

Figure 11 Structures of NHC ligands used in the preparation of (poly) heterobiaryls by Suzuki-Miyaura coupling...

The biarylphosphines 10 also reacted with the chloromethylated PS resin under basic conditions to give the PS-supported biarylphosphines 11 and 12 (Scheme 5) [38]. The resin-bound biaryl(dialkyl)phosphines 11 and 12 were the ligands designed for use in the palladium-catalyzed amination and Suzuki-Miyaura coupling of aryl halides, especially those of aryl chlorides. 

The non-cross-linked poly(acrylamide) 79 bearing the triarylphosphino groups was prepared from the acrylamide monomer and diphenyl(styryl) phosphine. The metal-directed self-assembly process between the non-cross-linked polymer ligand 79 and the palladium species afforded the networked supramolecular complex 80 [106, 109]. The complex catalyzed the Suzuki-Miyaura coupling [106,109] and the same concept, a tungsten-based self-assembly complex, has also been developed for the catalytic oxidation process. 

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