Telluroethers

Coordination chemistry of thioethers, selenoethers and telluroethers in transition metal complexes. S. G. Murray and F. R. Hartley, Chem. Rev., 1981, 81, 365-414 (748). 

Coordination chemistry of thioethers, selenoethers and telluroethers in transition metal complexes1... 

Recent developments in the coordination chemistry of selenoether and telluroether ligands6... 

Finally, Schiff base macrocycles incorporating telluroether functions are obtained by condensation of fe(2-formylphenyl)telluride with 1,2-diamino-ethane (analogues with Se incorporated have also been prepared).8,114... 

A variety of unsaturated alcohols with a cyclic structure and allyl phenols lead to bicycUc telluroethers. 

The dichlorotelluroethers are easily reduced to the parent telluroethers by treatment with TUD0.9... 

The synthetic utility of the described reactions is clearly illustrated by the reductive detel-luration of telluroethers with BujSnH, the entire telluration/detelluration process providing a cyclization under mild conditions for unsaturated alcohols. 

Reductive detelluration of cyclic telluroethers (typical procedure) To a solution of 2,3-diliydro-2-[(phenylteUuro)methyl]benzofuran (0.338 g, 1 mmol) in toluene (6 ml.) is injected TBTH (0.67 ml, 2.5 mmol) at room temperamre, and the resulting solution is stirred under reflux for 1 h. The solution is evaporated under vacuum and the residual yellowish oil subjected to Si02 column chromatography (eluting with benzene/hexane, 3 1) to give pure 2,3-dihydro-2-methylbenzofuran as a colourless oil (0.128 g (95%) b.p. 93-94°C/23 torr). 

Coordination Chemistry of Thioethers, Selenoethers, and Telluroethers in Transition- 1654 Metal Complexes... 

As observed previously for soft donor ligands such as thioethers and phosphines, mercury(n) reacts with selenoethers and telluroethers to form complexes of the general type HgLX2, where X is a halide or pseudohahde. In addition, mercury(II) forms complexes with various Se-donor ligands such as diethylselenocarbamate and selenourea. 

Diorganyl mono- and ditellurides are the best-known classes of organic tellurium compounds comprising symmetric and unsymmetric alkyl, aryl, and alkyl-aryl tellurides. In addition to acyclic tellurides, heterocychc aliphatic telluroethers as well as aromatic tellurophene-derivatives are known (for a review, see Ref 36). 

Several cyclic telluroethers and their derivatives are known, as exemplified by some common examples below (for a more detailed discussion, see Ref 36) ... 

Several types of telluroether (diorganyl tellmide) ligands are known. They can be monodentate or polydentate, acyclic, cyclic, and macrocyclic as well as hybrid telluroether ligands containing other donor atoms in addition to tellurium. Complexes with tellmoether ligands have seen extensive research activity in recent years (for two most recent reviews, see Refs. 27 and 35). 

Recent decades, however, have seen rapidly growing interest in this area. New synthetic approaches in the production of novel telluroether ligands have been designed. The advent of modem FT NMR techniques has enabled improved understanding of the tellurium-containing species in solution. The coordination chemistry of telluroether ligands has also proven to be much more varied than what was initially assumed. 

PdCl2(TeC4H8)2] is an example of a complex with heterocyclic telluroether ligand (Figure 21). The molecules show Te- -Cl close contacts of 3.462 and 3.472 A and consequently form dimeric units. l,3-dihydrobenzo[c]tellurophene (L) also behaves as a simple monodentate Te donor hgand with metals as exemphfied by [Mo(CO)6- L ] (n = 13). ... 

Scheme 5-32 shows a series of ferrocenyl compounds that can be formally considered as derivatives of the ferrocenyl chalcogenols, Fc-EH (E = O, S, Se, Te), including ferrocenyl ethers, thioethers, selenoethers and telluroethers. The analogous l,T-ferrocenediyl compounds, formally derived from fc(EH)2 (E = O, S, Se, Te), are presented in Scheme 5-33 (see Appendix). 

Arsenic(III) halides function as very weak Lewis acids towards thio- or seleno-ethers (no telluroether adducts are known). The products are hydrolytically unstable and extensively dissociated in solution. In all these complexes the As—S(Se) bonds are very long, indicative of weak. 

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