Silver complexes diphosphines

A small number of non-NHC silver compounds have been studied as potential anticancer agents. Berners-Price and coworkers synthesized bischelated silver(I) diphosphine and pyridiyl phosphine complexes, which proved to have in vitro cytotoxic properties against a variety of cancer cell lines tested, including cis-platin-resistant lines [28,29]. Additionally, a series of coordination polymers... 

By slowing down the rapid-ligand exchange reactions common in Ag(I) chemistry it seemed likely that a silver complex could be designed that would no be precipitated by Cr and thus might have in vivo antibacterial and anticancer activity. Bis-chelated Ag(I) diphosphine complexes appeared to be good candidates for investigation. 

Berners-Price SJ, Sadler PJ and Brevard C (1990) Tetrahedral, chelated, silver(I) diphosphine complexes. Rapid measurements of chemical shifts and couplings by two-dimensional P- ° Ag NMR spectroscopy. Magnetic Resonance in Chemistry 28 145-148. 

Most of the diphosphine complexes of silver known are of the type AgXP2, where X is a halide and P2 is a diphosphine. In general, they adopt dimeric structures in the solid state, with the exception of the silver chloride complex of 2,ll-bis(diphenylphosphinomethyl)benzo[c]-phenanthrene which is monomeric. 

A chiral BINAP-diphosphine complexed to silver , with fluoride as counterion, catalyses the enantioselective protonation of TMS-enolates, giving ketones with a tertiary asymmetric a-carbon in up to 99% ee.294... 

Figure 2 Structures of some silver(I) complexes with bridging bidentate diphosphines...

Exploration of new complexes with useful antimicrobial activities has stimulated extensive development of synthetic chemistry of silver(I) complexes. The incorporation of novel ligands can moderate the physical and chemical properties of complexes. For example, the bis(diphosphine)silver(I) complexes (which are analogues of the bis(diphosphine)gold(l) complexes with promising antitumor activity compromised by their antimitochondrial activity) were examined for antitumor and antimicrobial activity by... 

Silver] I)-chiral diphosphine complexes also are available for asymmetric aldol re-... 

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