Organometallic compounds amination

Zirconium tetrachloride is instantly hydrolyzed in water to zirconium oxide dichloride octahydrate [13520-92-8]. Zirconium tetrachloride exchanges chlorine for 0x0 bonds in the reaction with hydroxylic ligands, forming alkoxides from alcohols (see Alkoxides, METAl). Zirconium tetrachloride combines with many Lewis bases such as dimethyl sulfoxide, phosphoms oxychloride and amines including ammonia, ethers, and ketones. The zirconium organometalLic compounds ate all derived from zirconium tetrachloride. 

Although inhibitors are deliberately added to the silicone formulation to control cure rate, unwanted cure inhibition can be caused by other species that react to form strong complexes with the platinum catalyst. Most notable of these undesired inhibitors include organotin and other organometallic compounds, sulfur, polysulfides, polysulfones or other sulfur-containing materials, amines, urethanes or amine-containing materials, unsaturated hydrocarbons in plasticizers, and some solder flux residues. 

Low surface energy substrates, such as polyethylene or polypropylene, are generally difficult to bond with adhesives. However, cyanoacrylate-based adhesives can be effectively utilized to bond polyolefins with the use of the proper primer/activa-tor on the surface. Primer materials include tertiary aliphatic and aromatic amines, trialkyl ammonium carboxylate salts, tetraalkyl ammonium salts, phosphines, and organometallic compounds, which are initiators for alkyl cyanoacrylate polymerization [33-36]. The primer is applied as a dilute solution to the polyolefin surface, solvent is allowed to evaporate, and the specimens are assembled with a small amount of the adhesive. With the use of primers, adhesive strength can be so strong that substrate failure occurs during the course of the shear tests, as shown in Fig. 11. 

Cleavage of amine ethers with organometallic compounds... 

The majority of gold(I) carbene complexes are pure organometallic compounds and the are out of the scope of this work. Some halide or triphenylphosphine carbene complexes are known and they will be considered here. Nucleophilic addition of alcohols or amines to gold-coordinated isocyanides is one of the best-established methods to obtain gold carbene derivatives. The reaction of H[Au(CN)2] with propene oxide and estirene oxide yields (cyano)carbene complexes (380) avoiding the intermediate step.2257 A cyclic carbene compound is obtained by reaction of a dinuclear isocyanide with amine (Scheme 32).2258... 

Addition of organometalic compounds to nitrones is known as an efficient method of enantioselective synthesis of primary amines that can be easily obtained by the reduction of hydroxylamines which are the products of nucleophilic addition. 

The reaction of organometalic compounds with nitrones can be applied not only to the synthesis of stable nitroxyl radicals but also to the preparation of optically active secondary amines (Scheme 2.162) (617, 618). 

Lithium t-butyl A-tosyloxycarbamate, Bu C CNTos Li+, is an electrophilic aminating agent for organometallic compounds RM (MeLi, BuLi, j-BuLi and PhCu) to give,... 

The tertiary amines 96 react with organometallic compounds to afford disubstituted products 105117. 

The importance of tertiary amines in the photochemically induced electron transfer reactions has also been addressed5. Direct irradiation of aromatic or aliphatic amines often leads to the scission of C—N, N—H or C—H bonds that lead to the subsequent chemical reactions by radical pathways6. In this section, photochemical reactions of amines reported since 1978 will be considered with emphasis on photoinduced electron transfer. Photochemical reactions of inorganic and organometallic compounds will not be included unless photochemistry of amine moieties is the primary interest. 

A,A-disubstituted derivatives 1-5. Amination of Group 1, 2, 11 and 12 organometallic compounds and a-metallated carbonyl compounds with these reagents takes place by a direct introduction of the R1R2N+ group to carbanions and enolates and for completion the reactions require only hydrolytic work-up (Scheme 3). 

A variety of basic (nucleophilic) initiators have been used to initiate anionic polymerization [Bywater, 1975, 1976, 1985 Fontanille, 1989 Hsieh and Quirk, 1996 Morton, 1983 Morton and Fetters, 1977 Quirk, 1995, 1998, 2002 Richards, 1979 Szwarc, 1983 Young et al., 1984]. These include covalent or ionic metal amides such as NaNFU and LiN(C2H5)2, alkoxides, hydroxides, cyanides, phosphines, amines, and organometallic compounds such as n-C4H9Li and <)>MgBr. Initiation involves the addition to monomer of a nucleophile (base), either a neutral (B ) or negative (B ) species. 

Water, alcohols, ethers, or amines can cause inhibition of ionic polymerization. However, these substances can act in different ways according to their concentration. For example, in polymerizations initiated by Lewis acids (BF3 with isobutylene) or organometallic compounds (aluminum alkyls), water in small concentrations behaves as a cocatalyst, but in larger concentrations as an inhibitor (reaction with the initiator or with the ionic propagating species). 

For some monomers (e.g., nitroethylene and 2-cyano-2,4-hexadienoic acid ester, CH3-CH=CH-CH=C(CN)-COOR), anionic polymerization can be conducted in aqueous alkaline solution. Other anionic initiators are Lewis bases, e.g., tertiary amines or phosphines, and organometallic compounds (see Sect. 3.2.1.2). Since the polarizability of unsaturated compounds depends very much on the substituents and on the solvent used, there are considerable differences in the effectiveness of the initiators mentioned. 

Anionic polymerization can be initiated with tertiary phosphines or amines, with organometallic compounds or with alcoholates. With all of these, initiation occurs by nucleophilic attack on the positive carbonyl carbon atom ... 

The addition of isocyanates to hydroxy compoimds is inhibited by acid compounds (e.g., hydrogen chloride orp-toluenesulfonic acid) on the other hand, it can be accelerated by basic compounds (e.g., tertiary amines like triethylamine, N,hl-dimethylbenzylamine, and especially l,4-diazabicyclo[2.2.2]octane) and by certain metal salts or organometallic compounds (e.g., dibutyltin dilaurate, bismuth nitrate). These catalysts are often effective in amounts of much less than 1 wt%. 

A. Lattes, Afinidad 1972, 2953 -2970 . .Application of Organometallic Compounds to the Synthesis of Amines and Nitrogenated Heterocycles". 

Organometallics are generally strong nucleophiles and bases. They react with weak acids, e.g. water, alcohol, carboxylic acid and amine, to become protonated and yield hydrocarbons. Thus, small amounts of water or moisture can destroy organometallic compounds. For example, ethylmag-nesium bromide or ethyllithium reacts with water to form ethane. This is a convenient way to reduce an alkyl halide to an alkane via Grignard and organolithium synthesis. 

The Conversion of Organometallic Compounds to Amines Amlno-de-metallation... 

For the addition of an organometallic compound to an imine to give a primary amine, R in RCH=NR would have to be H, and such compounds are seldom stable (6-13). However, the conversion has been done, for R = aryl, by the use of the masked reagents (ArCH=N)2S02 [prepared from an aldehyde RCHO and sulfamide (NH2)2S02]. Addition of R MgX or R"Li to these compounds gives ArCHR"NH2 after hydrolysis.481... 

Cleavage of amine ethers with or-ganometallic compounds 0-93 Reaction of organometallic compounds with aziridines 0-97 Alkylation of amines... 

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