Copper aryloxides

The reactivity of copper aryloxides towards a variety of heterocumulenes has been investigated. " " Insertion of RNCS (R = Me, Ph) into copper(i) aryloxide bonds has been shown to lead to a variety of A-alkylamino(aryloxy)methanethiolato complexes depending on the natnre of the ancillary hgands. In the absence of any other donor ligation a clnster componnd, [Cn /Li2-SC(=NPh)(OAr) ]6 has been characterized from the insertion of PhNCS into a Cn-4-methylphenoxide bond. " Recently the effect of orf/zo-substitnents upon the oligomerization of Cu(i) complexes formed by insertion of CS2 and PhNCS into Cu-OAr bonds has been carried out. " Some of the insertion reactions have been shown to be reversible. 

Cai et al. (71) examined the use of dinuclear copper complexes as catalysts in the cyclopropanation reaction. Their ligand design, based on the success exhibited by the Aratani system, incorporates a diimine aryloxide. A comparison of the mononuclear catalyst 99 with the corresponding dinuclear catalyst 100 showed certain modest benefits conferred by the latter, Eq. 52. The authors note that these catalysts are effective at ambient temperature but isolated yields are higher at 50°C with no loss in enantioselectivity. 

In a study published concurrently with the Evans bis(oxazoline) results, Jacobsen and co-workers (82) demonstrated that diimine complexes of Cu(I) are effective catalysts for the asymmetric aziridination of cis alkenes, Eq. 66. These authors found that salen-Cu [salen = bis(salicylidene)ethylenediamine] complexes such as 88b Cu are ineffective in the aziridination reaction, in spite of the success of these ligands in oxo-transfer reactions. Alkylation of the aryloxides provided catalysts that exhibit good selectivities but no turnover. The optimal catalyst was found to involve ligands that were capable only of bidentate coordination to copper. 

Copper(I) alkoxides (CuOR) and aryloxides (CuOAr) are yellow substances that can be made, for example, by the reactions... 

Dimeric or polymeric compounds are also known for alkoxides or aryloxides, for example, [Cu(OPh)2en]2-2PhOH, which has distorted sp copper. 

Wycliff C, Samuelson GA, Munirathinam N. Reversible insertion of methyl isothiocyanate into copper (1) aryloxides. Inorg Chem 1996 35 5427-34. 

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