Alkyl, amines phosphines

Anionic polymerizations are initiated in polar systems by bases and Lewis bases. For example, alkali metals, alcoholates, metal ketyls, metal alkyls, amines, phosphines, and Grignard compounds act as initiators. However, the polymerization mechanism does not depend on the nature of the initiator alone. For example, tertiary amines and phosphines do not only initiate anionic polymerizations under certain conditions, they can also initiate zwitterion polymerizations. In addition, polyinsertions can proceed in less polar systems. Thus, anionic polymerizations are often carried out in polar solvents. Ethers and nitrogen compounds, such as tetrahydrofuran, ethylene glycol dimethyl ether (glyme), diethylene glycol dimethyl ether (diglyme), pyridine, and ammonia are most commonly used. 

Alkylnickel amido complexes ligated by bipyridine have been prepared that undergo reductive elimination of V-alkyl amines (Equation (54)).207,208 Unlike the phosphine-ligated palladium arylamides, these complexes underwent reductive elimination only after oxidation to nickel(III). Thermally induced reductive elimination of alkylamines from phosphine-ligated nickel complexes appears to occur after consumption of phosphine by arylazides 209... 

The carbonyl group of formaldehyde is highly susceptible to nucleophilic attack and this monomer can be polymerized with almost any base. Metal alkyls, alkoxides, phenolates, and carboxylates, hydrated alumina, amines, phosphines, and pyridine are effective in polymerizing formaldehyde. 

Trimerization of imidates is a valuable route to 1,3,5-triazines. Imidates can be considered as activated nitriles and cyclotrimerize more readily. Most symmetrical 2,4,6-trialkyl-1,3,5-triazines are easily formed, although large alkyl substituents may give rise to steric hindrance (61JOC2778). Symmetrical isocyanurates (525) are readily available from isocyanates, RNCO catalysts include tertiary amines, phosphines and sodium methoxide. Aldehydes RCHO and ammonia give hexahydro-1,3,5-triazines (526), known as aldehyde ammonias (73JOC3288). 

The solubility of rare earth hydrides in organic solvents is increased by appropriate additives, too. For this purpose the hydrides are reacted with electron-donor ligands such as alkyl benzoates, alkyl propionates, alkyl tolu-ates, dialkylethers, cyclic ethers, alkylated amines, N,N -dimclhylacelamide, AT-methyl-2-pyrrolidone, trialkyl and triaryl phosphines, trialkyl phosphates and triaryl phosphates, trialkyl phosphates, hexamethylphosphoric triamide, dimethyl sulfoxide, etc. Prior to use as a polymerization catalyst the prereacted mixture of the rare earth hydride plus the additive is prereacted with Al-alkyl-based Lewis acids in the temperature range of 60-100 °C for 10 min to 24 h [351,352]. 

The synthesis of the cation is typically performed by alkylation of an amine, phosphine or sulfide, most commonly using an alkyl halide [ ]. In most cases the reaction is carried out with chloro-, bromo- and iodoalkanes as readily available alkylating reagents, with the reaction conditions becoming more gentle changing from chloride to bromide to iodide, as can be expected for nucleophilic substitution... 

In papers published back-to-back in 1996, Hartwig and Buchwald reported amination chemistry with palladium complexes of DPPF and BINAP as catalysts [50,86]. These palladium complexes provided animations of aryl bromides and iodides with primary alkyl amines, with cyclic secondary amines, and with anilines. It is ironic that the amination chemistry was first discovered by using a particularly labile phosphine, but was dramatically improved by the use of chelating ligands. 

The reaction of palladium reagents with amines, phosphines, and other organic ligands to produce chelated complexes with Pd-C bonds is the Cyclometalation reaction (equation 7). It has been used to synthesize thousands of complexes with Pd-alkyl and Pd-aryl bonds. These complexes are beginning to be used as very stable, high turnover number catalysts and as intermediates in the synthesis of complex natural products. The scope and limitations of this reaction are detailed in Section 8. 

Reaction of [Mn(R)(CO)j] with neutral nucleophiles is by far the most widely studied type of reaction for [Mn(R)(CO)s] compounds. The reaction usually involves addition of the neutral neucleophile, L, and is accompanied by CO insertion/alkyl migration to form an acyl species [Eq. (29)]. L is usually a tertiary phosphine (PR3), an alkylated amine (RNH2), or free carbon monoxide. Besides being a carbon-carbon bond forming reaction of fundamental importance, alkyl migration reactions of transition metal alkyl species have direct relevance to catalysis, especially for the 0X0 or hydroformylation process (2), the Monsanto acetic acid synthesis (2), and the synthesis of ethylene glycol (94). 

The synthesis of TSOSs is analogous to non-functionalized ILs. Indeed, the same key steps can be applied depending on the nature of the cation and the anion. Quatemisation of tertiary amines, phosphines and sulfides with a functionalized alkyl halide affords the desired functionalized ammonium, phosphonium and sulfonium halides in usually... 

The alkyls are Lewis acids, combining with donors such as amines, phosphines, ethers, and thioethers to give tetrahedral, four-coordinate species. Thus Me3NAlMe3 in the gas phase has C3u symmetry with staggered methyl groups.51 With tetramethylhydrazine and (CH3)2NCH2N(CH3)2, 5-coordinate species that appear to be of the kind shown in (9-VII) are... 

The direct ammonolysis of (3-bromopropyl)phosphonic acid yields 36% of the 3-amino acid. The reaction between (chloromethyl)phosphonic acid and the less basic aniline requires an extensive period, even at 160-170 °C. Nevertheless, extensive use has been made of the direct displacement of chlorine from (chloromethyl)phosphonic acid by higher boiling primary amines", and that in alkyl(chloromethyl)phosphinic esters by glycine Reactions which involve secondary amines, particularly A-substituted glycines, and... 

Herrmann, W. A. Koecher, C. Goossen, L. J. Artus, G. R. J. Chem. Eur. J. 1996,2,1627. A combined synthesis involving the formation of the halide salt and an in situ anion metathesis with a sodium salt was also developed, but requests very long reaction time (typically two weeks) Wasserscheid, R HUgers, C. Boesmann, A. Single step preparation of ionic fluids by alkylation of amines, phosphines, imidazoles, pyridines, triazoles, and pyrazoles with alkyl halides followed by ion exchange. Eur. Rat. AppL 1182197, 2002 Branco, L. C. Rosa, J. N. Moura Ramos, J. J. Afonso, C. A. M. Chem. Eur. J. 2002, 8,3671. 

Fluoroalkyl(aryl)iodonium salts are the most stable and practically important class of alkyl(aryl)iodonium derivatives. The application of such salts as electrophilic fiuoroalkylating reagents was reviewed in 1996 by Umemoto [1017]. Perfluoroalkyl(phenyl)iodonium trifiates (FITS reagents) 764 are efficient perfluoroalky-lating reagents toward various nucleophiUe substrates, sueh as arenes, carbanions, alkynes, alkenes, carbonyl compounds, amines, phosphines and sulfides [1017]. Scheme 3.300 shows several representative examples of electrophilic perfluoroalkylations using FITS reagents. 

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