Ligands phosphanes

As ligands, phosphanes have proven to be useful (Table 7, No. 2-4). Poly(l,4-paraphenylene) is obtained on a preparative scale starting from aromatic dihalides (Table 7, No. 3, 4). The electrochemical generation and... 

Loeber C, Wieser C, Matt D, De Cian A, Fischer J, Toupet L. Cavity-shaped phos-phane ligands phosphane-amide hybrids based on a caUx[4]arene matrix and their chelating behavior towards platinum and rhodium. Bull Soc Chim Fr 1995 132(2) 166-77. 

The versatility of tertiary phosphane ligands in coordination and organometallic chemistry. R. Mason and D. W. Meek, Angew. Chem., Int. Ed. Engl., 1978,17,183-194 (138). 

Keywords Group 13 metals (aluminum, gallium, indium, thalhum), Ambidentate ligands. Phosphorus-nitrogen bidentate ligands, Pyridyl phosphanes, Aminoiminophosphoranes, Lewis acid catalysis... 

Following the general trend of this account, monodentate phosphinous amide ligands and bidentate AT-phosphino phosphinous amides or bis(amino-phosphanes) are included in the following discussion, but not other bidentate ligands bearing additional, different phosphorus functionalities, as for instance phosphinous amide-phosphane bidentate ligands. 

As base B several electron donors can be employed, e.g. amines 127), hydrazines128), amine oxides129, ethers126, phosphanes 130>131, and even charged ligands such as halogen anions 126) and many others 126). There may be formed either 1 1 or 1 2 adducts as in Eq. (7), an equilibrium being assumed to be established between these two adducts ... 

Trifluorophosphane can behave as a /x3 donor towards a triangular palladium core.559,360 The symmetrically bridging / -coordination mode has little precedent for tertiary ligands based on Group 15 atoms. The synthesis of a Pd1 dimer featuring a strongly bonded symmetrically bridging /i2-phosphole unit, which is the first example of this coordination mode for a tertiary phosphane, has been reported.561... 

Phosphane-free ligands such as dipyridyl—amide-based systems incorporated into suitable monomers were used for the preparation of well-defined heterogeneous Heck systems via ringopening metathesis polymerization (Figure 24).183,184... 

The stabilized anion 134 also attacks the terminal vinylic position of 131 exclusively to give cyclopropylideneethyl derivatives 135, which are synthetically useful building blocks [69], The use of chiral phosphanes as ligands leads to optically active methylenecyclopropane derivatives. (Scheme 47)... 

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