Synthesis, structure, and catalytic activity of chiral silver(I) and copper(II) complexes with biaryl-based nitrogen-containing ligands

Synthesis, Characterization, and Variable-Temperature NMR Studies of Silver(I) Complexes for Selective Nitrene Transfer

“…The C–N bond is present in an array of diverse molecules with significant biological and therapeutic value. One effective strategy for streamlining amine synthesis involves the direct introduction of a new C–N bond at a specific CC or C–H group in a substrate through metal-catalyzed nitrene transfer to yield an aziridine or an amine product, respectively. − However, the limited ligand scaffolds that support metal-catalyzed nitrene transfer have resulted in a strong element of substrate control over the chemoselectivity and site selectivity of an amination event. ,,, In contrast, our recent work using silver­(I) complexes supported by nitrogen-donor ligands enables unprecedented flexibility and tunability in nitrene transfer that proceed under the auspices of catalyst control. − However, the design of second-generation catalysts is challenging because of the lability of Ag–N bonds and their dynamic behavior, which can influence the nuclearity of the complex in solution. − …”

Catecholase Activities of Copper(II) Complexes With N4 Ligands

“…[41][42][43][44][45][46][47] On the other hands, N 4 ligands derived from 2,2 0 -ethylenedianiline showed a characteristics of forming polymeric or macrocyclic metal coordination compounds, which are suitable for investigating novel geometries and electronic properties of such coordination compounds. 22,24,[48][49][50][51] We have been interested in developing N 4 ligands, which can form monomeric coordination compounds, derived from 2,2 0 -ethylenedianiline to diversify the ligand candidates for biomimetic complexes and to compare the coordination abilities of N 4 ligands derived from tren and 2,2 0 -ethylenedianiline.…”

Silver comes into play: Henry reaction and domino cycloisomerisation sequence catalysed by [Ag(i)(Pc-L)] complexes

“…[8][9][10] No need for a stoichiometric amount of a base, metal-catalysts, 11-15 enzymes 16,17 or organocatalysts [18][19][20] can efficiently promote the Henry reaction. Among the metal complexes commonly employed as catalysts, copper(I) [21][22][23][24][25][26][27][28][29][30] and copper(II) 11,[31][32][33][34][35][36][37][38][39][40][41][42][43][44] complexes play a prominent role, whereas, to the best of our knowledge the activity of silver salts and complexes have rarely been tested. In several cases reported in the literature, the replacement of Cu with Zn gave comparable results but in some of them a reversed enantioselectivity was observed.…”

“…27,32,33,42,45 Cu-catalysed reactions are believed to proceed by a monometallic form of active species whereas there is strong evidence of the involvement of a multimetallic species as actual catalyst in Zn(II) promoted Henry reactions. 26 Surprisingly, such a correlation in reactivity with silver has never been made and the few examples appeared in the literature report that silver salts either failed in promoting the reaction, 40,46 or gave very poor yields. 36,47 In the past few years, our attention has turned to the introduction of a pyridine moiety into the skeleton of tetraazamacrocycles, with the aim to obtain ligands with increased conformational rigidity and different basicity.…”