Phosphine, methyl triphenyl-, complexes with

The results summarized in Table 25 show that nickel complexed with a bidentate phosphine [NiCl2[Ph2P(CH2)3PPh2]j is less efficient than nickel complexed with triphenyl phosphine [NiCl2(PPh3)2] and the selectivity in favor of the 5, 2 product is moderate in both cases, even with primary sulfides. In the sole examples of cinnamyl methyl sulfide, the selectivity is excellent toward the 8, 2 product 276. 

A related group of compounds is that of the gold(III) dimethyl(alkoxycarbonyl) complexes, accessible by the reaction of carbon monoxide with dimethyl(alkoxy)(triphenyl-phosphine)gold(III), which is prepared in situ from cw-[AuIMe2(PPli3)] and sodium alkoxide in methanol (equation 80)353,359. Thermolysis of the methoxycarbonyl complex in benzene leads to the reductive elimination of methyl acetate and ethane, indicating competition between the two modes of decomposition illustrated in Scheme 27. The reaction of the same complex with electrophiles such as hydrogen chloride proceeds with liberation of carbon monoxide and methanol, as illustrated in equation 81. 

An example of a large scale application of this concept is the Ruhrchemie/ Rhone Poulenc process for the hydroformylation of propylene to n-butanal, which employs a water-soluble rhodium(I) complex of trisulfonated triphenyl-phosphine (tppts) as the catalyst [103]. The same complex also functions as the catalyst in the Rhone Poulenc process for the manufacture of the vitamin A intermediate, geranylacetone, via reaction of myrcene with methyl acetoacetate in an aqueous biphasic system (Fig. 1.35) [104]. 

In 2007, the new dysprosium complex Dy(PM)3(TP)2 [PM= l-phenyl-3-methyl-4-isobutyryl-5-pyrazolone and TP = triphenyl phosphine oxide] was reported. A series of devices with various structures were fabricated to investigate the EL performance of Dy(PM)3(TP)2. The best device with the structure ITO/CuPc (15 nm)/Dy complex (70 nm)/BCP (20 nm)/AlQ (30 nm)/LiF (1 nm)/Al (100 nm) exhibited maximum brightness 524 cd m , current efficiency 0.73cdA and power efficiency 0.161mW The low PL quantum yield (3.5%) of the complex caused poor EL performance [75]. 

S. Davies has used an iron complex as an auxiliary for the asymmetric cyclopro-panation of a,P-unsaturated carbonyls [105]. The iron acyl is most stable in the s-cis conformation, as illustrated in Scheme 6.27, in order to avoid severe interactions between the iron ligands and R. Coordination of the Simmons-Smith reagent to the carbonyl oxygen, anti to the iron, forces the alkene moiety out of conjugation and approximately orthogonal to the carbonyl. Because of the bulky triphenyl phosphine in the rear, this rotation can only be towards the front. Transfer of the methylene via the illustrated transition state accounts for the observed diastereoselectivity. Oxidation with bromine removes the iron acyl and derivatization with a-methyl-benzyl amine allowed evaluation of the stereoselectivity. 

Irradiation of (methyl acrylate)iron tetracarbonyl in the presence of excess methyl acrylate at 20° forms a ferracyclopentane product. Thermal reaction of the metallocyclopentane with carbon monoxide or triphenyl-phosphine affords a cyclopentanone derivative (Grevels et al., 1974). Similar ferracyclopentane complexes may be involved as intermediates in the well-known cyclopentanone formation from iron carbonyls and strained olefins (for example, Grandjean et al., 1974 Mantzaris and Weissberger, 1974). 

Nucleophilic attack on phosphorus is not restricted to phosphonium salts, phosphines, and phosphoranes as Gottfried Markl has brilliantly demonstrated. Phenyllithium binds readily to the heteroelement of the faintly yellow 2,4,6-triphenyl-1-phosphabenzene (2,4,6-triphenylphosphorine). The resulting ate complex (69, Scheme 1-48) gives with methyl iodide the crystalline deep red 1-methyl-1,2,4,6-tetraphenyl-1 -phosphabenzene (76%). ... 

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