Halides, aryl, arylation phosphines

Palladium-catalyzed aromatic C—O bond formation is less developed than palladium-catalyzed aryl amination. Except when the aryl halide is strongly electron deficient,107-110 catalysts ligated by the conventional aryl phosphines such as DPPF and BINAP are ineffective for coupling of... 

Phenylurefbanes, 58, 10 Phosgene, 57, 46 Phosphine, diphenyl-, 56,45 Phosphine-mckcl catalyst, 58, 129 PHOSPHINE-NICKEL CATALYZED COMPLEX CROSS-COUPLING OF GRIG-NARD REAGENTS WITH ARYL AND ALKENYL HALIDES, 58, 127 Phosphine, phenyl-, bis(3-dimethylamino-piopyl)-, 55, 128 Phosphine, triphenyl-, 56, 81 Phosphomum, [ 4-(4-rne thoxy phenyl)-2-butenyl) triphenyl, iodide, 56, 81 Phosphomum, 2-octadecenyltnphenyl-, iodide, 56, 81... 

Many types of palladacyclic complexes have been used as precursors to catalysts for a variety of coupling processes146,147. Mixtures of dimeric palladacycles containing bridging halide, acetate or trifluoroacetate ions and a phosphine or carbene ligand have been studied as catalysts for the animation of aryl halides. The isolated phosphine adducts can also be applied in catalysis. 

A comprehensive n.m.r. investigation of the boron hydride and halide addition compounds with a number of alkyl- and aryl-phosphines is reported by Rapp and Drake.220 The H data point to a relationship between... 

A detailed study of the photochemical cyclization of norbornadiene to quadricyclane using aryl phosphine copper(I) halides has been reported. The quadricyclane (144) is formed on irradiation of the norbornadiene (145) at 366 nm. The quantum yield (0.68) for the process is high. The influence of triplet sensitizers ( metal complexes, biacetyl and acetophenone) were found to be less efficient ( ct> = 0.1). The authors suggest that the lowest singlet state of norbornadiene is much more reactive than the triplet state. ... 

Further esterification of monobenzyl benzylphosphonate may be carried through the Mitsunobu procedure, the best yields being achieved using the potassium salt of the substrate. Monoesters of iV-protected (1-aminoalkyl)phosphonic acids are further esterified by alcohols in the presence of BOP-type reagents [(l-aminoalkyl)alkylj- and [(l-aminoalkyl)aryl]-phosphinic acids, again as their potassium salts, have been converted into esters by reactive alkyl halides in the presence of 18-crown-6 ether (see also reference The... 

Table II gives examples of several compounds of Os (II) showing that osmium in a formal oxidation state of +2 can bind N2 in the presence of a wide range of other hgands, NH3, NH3 + N2, halide, alkyl and aryl phosphines. In such compounds, the presence of other ligands that can accept d electrons from the metal reduces the extent of metal-to-hgand 7T electron transfer in the metal—N2 bond. This is indicated by an increase in the N2 stretching frequency, other things being equal. A further example is cw-[Os (NH3)4CO.N2] in which vn2 is raised to 2180 cm ...

Nickel (II) salts effectively catalyze the reaction of Grignard reagents with vinyl and aryl halides. A soluble phosphine complex, Ni(Ph2PCH2CH2PPh2)2Cl2, has been shown to be an effective catalyst. " With secondary Grignard reagents under... 

Phosphinous acids represent a promising new class of phosphorus ligands for Suzuki cross-couphngs of unactivated aryl chlorides. The hydrolysis of diorgano-phosphorus halides generates secondary phosphine oxides in an equilibrium with their less-stable phosphinous acid tautomers (Equation 2.29). 

The most intensely studied metal-catalysed reaction producing P-stereogenic phosphines is the Pd-catalysed phosphination of aryl halides with secondary phosphines and derivatives, a cross-coupling reaction (Scheme 6.19). 

SCHEME 20.62 Reaction of aryl halides with H-phosphinate ester. 

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