Suzuki-Miyaura cross-coupling ligands

Since the first reports of Suzuki-Miyaura cross-coupling with carbenes as ancillary ligands [122,123], increasing attention and efforts have been devoted to this transformation [124-140]. 

A convenient and effective palladium-catalysed Suzuki-Miyaura cross coupling reaction of deactivated aryl chlorides with phenylboronic acid utilised the 1,3-diazepinium salts 107 as in situ precursors of the palladium ligands. These salts were prepared from the diamines 106 and cyclocondensation with triethyl orthoformate <05SL2394>. 

Martin R, Buchwald SL (2008) Palladium-catalyzed Suzuki-Miyaura cross-coupling reactions employing dialkylbiaryl phosphine ligands. Acc Chem Res 41 1461-1473... 

Arylation of ketones, aryl amination and suzuki-miyaura cross coupling using a well-defined palladium catalyst bearing an w-heterocyclic carbene ligand... 

ARYLATION OF KETONES, ARYL AMINATION AND SUZUKI-MIYAURA CROSS COUPLING USING A WELL-DEFINED PALLADIUM CATALYST BEARING AN /V-HETEROCYCLIC CARBENE LIGAND... 

Both, for donor- and acceptor-substituted aryl bromides 24, quantitative conversions could be reached indeed, even for 24 with X = Cl and X = OTf, conversions of 90% were achieved. For X = Cl, the presence of the phosphine ligand L was necessary moreover, the couplings could be carried out in a homogeneous dimethyl formamide (DM F)/water solution at room temperature, and were complete within a few hours. As could be seen in initial reports of Suzuki-Miyaura cross-coupling [6], the boron component was also used in small... 

Scheme 1.13 The Suzuki-Miyaura cross-coupling of 4-chlorophenyl triflate leading regioselectively to different products using PCyj or PtBuj as the ligands for Pd(0).

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