Synthesis, Biological Evaluation and Stability Studies of Novel Symmetrical and Non-Symmetrical 11th Group-NHC Complexes

Recently metallodrug chemistry bearing N-heterocyclic carbene (NHC) supporting ligands has experienced a new rebirth. Our research group, during the last 7 years, has developed different classes of coinage metal-NHC complexes obtained from the precursors {[H2B(BnTzH)2]Br},1 {[H2B(pNO2BnTzH)2]Br} {[HTz(pNO2Bn)2]Br}2. Recently we have focused the research work on the synthesis of new coinage metal-NHCs complexes obtained from the water soluble ligands Him1R,3RCl (R = COOCH3, COOCH2CH3 or CON(CH2CH3)2)3 or the zwitteronic symmetrical NHC ligands NaHIm1R,3R,4R’’ (R = (CH2)3SO3-, R’’ = H, CH3)4 (Figure 1), NaHBzim1R,3R (R = (CH2)3SO3-) and non-symmetrical NHC ligands NaHIm1R,3R’ (R = (CH2)3SO3-, R’ = CH2C6H5), {[HBzim1R,3R’]Br} (R = (CH2)3SO3Na, R’ = CH2C6H5) and the related copper(I)- and silver(I)-NHC complexes.5 Finally we studied the cytotoxic activity and the stability of the NHC complex classes developed by our research group.