Amines thioethers

Optically active amine-thioether ligands (492) have been investigated in nickel-catalyzed asymmetric cross-coupling reactions of Grigard reagents.1338... 

Technetium compounds with amine/thioether coordination are the cationic trans-dioxotechnetium(V) complexes [Tc02(N2S2)]+. The complex in which N2S2 is l,4-dithia-8,ll-diazacyclotetradecane was prepared via an exchange reaction of NBu4[TcOBr4] with the ligand and fully characterized by X-ray crystal structure determination [109,110]. The coordination around technetium... 

Porath, 1974). B/s-oxirane compounds also can be used to introduce epoxide groups into soluble dextran polymers in much the same manner (Boldicke et al., 1988 Bocher et al., 1992). The epoxide group reacts with nucleophiles in a ring-opening process to form a stable covalent linkage. The reaction can take place with primary amines, sulfhydryls, or hydroxyl groups to create secondary amine, thioether, or ether bonds, respectively (Chapter 2, Section 1.7). 

Limitations of the Pd(II)-catalyzed cydoisomerization/dimerization are strongly coordinating groups such as pyridyl groups, amines, thioethers or halogens on the allene [61]. With 96, AuC13 delivered products 102, which are constitutional isomers of the dimers of the Pd(II)-catalyzed reactions (Scheme 15.27) [62]. Compounds 102 are always accompanied by the monosubstituted furans 99. Furthermore, these catalysts were highly reactive and allowed a much faster reaction than Ag(I) or Pd(II) under the same conditions. 

Sub = Phosphines, tertiary amines, thioethers, sulfoxides, 7r-bonds... 

Highly Lewis basic and nucleophilic functional groups are not compatible with zinc carbenoids. The methylation or ylide formation of heteroatoms is one of the most important side reactions of these reagents. For example, amines, thioethers and phosphines readily react with the zinc reagents to generate ammonium salts", sulfonium" and phosphonium ylides" ". Terminal alkynes generally lead to a large number of by-products". ... 

The Pauson Khand reaction is compatible with a wide variety of functionalities, such as ethers, alcohols, tertiary amines, thioethers, ketones, ketals, esters, tertiary amides, carbamates, and benzene, furan, and thiophen rings. Disubstituted alkynes, alkenes with bulky allylic substituents, and trisubstituted alkenes frequently afford reduced yields of products. Because of the reduced ability of sterically hindered alkenes to coordinate and undergo insertion, insertion of one or more molecules of alkyne occurs instead. 

Finally, redox potentials of thioether complexes also indicate the n-acidity of the ligands. Coordination to thioethers invariably raises redox potentials relative to those of analogous aquo or amine complexes. Thus electrochemical studies of [M(bpy)2L2]" complexes (M = Ru, Os) with L = amine, thioether, and phosphine ligands) [27] show that thioethers exceed amines in stabilizing the low (n = 2) oxidation state, but fall short of phosphines. Part of this increment stems from the limited ability of thioethers to neutralize charge through a-donation. Nevertheless, n-acceptance probably contributes significantly as well. 

C. Copolymers with Ether-Thioether and Amine-Thioether Spacers... 

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