Argentate( i ) and ( iii ) complexes as intermediates in silver-mediated cross-coupling reactions

The homoleptic silver(I) compound [PPh ][CF AgCF ] (1) provides a convenient entry to the homoleptic silver(III) derivative [PPh ][Ag(CF ) ] (2). Once isolated as pure substances, these compounds exhibit marked thermal stabilities. Their structural and spectroscopic properties have been experimentally established. Moreover, their electronic structures have been calculated by theoretical methods. The electronic structure of the oxidized species [Ag(CF ) ] provides a new case of ligand-field inversion caused by the CF ligands.

Section: Methodsmentioning

confidence: 72%

“…Compound 1 , however, shows superior thermal stability and has therefore definite advantages for synthetic purposes. It is also worth noting that the relative stability of the methyl silver( I ) derivatives [CX 3 AgCX 3 ] − follows the order: CH 3 <CHF 2 <CF 3 . Schlenk‐type exchange processes [Eq.…”

Section: Methodsmentioning

confidence: 99%

Homoleptic Trifluoromethyl Derivatives of Ag^I and Ag^III

Joven-Sancho

Baya

Martín

et al. 2018

“…In addition, it also afforded severalo ther fragment ions stemming from ligand dissociation and ligand decomposition reactions. In contrast, the formation of the above-mentionedd imerization product C 48…”

Section: Species Formed By Transmetalationmentioning

confidence: 93%

Formation of Transient Anionic Metal Clusters in Palladium/Diene‐Catalyzed Cross‐Coupling Reactions

Kolter

Koszinowski

2019

Self Cite

Despite their considerable practical value, palladium/1,3‐diene‐catalyzed cross‐coupling reactions between Grignard reagents RMgCl and alkyl halides AlkylX remain mechanistically poorly understood. Herein, we probe the intermediates formed in these reactions by a combination of electrospray‐ionization mass spectrometry, UV/Vis spectroscopy, and NMR spectroscopy. According to our results and in line with previous hypotheses, the first step of the catalytic cycle brings about transmetalation to afford organopalladate anions. These organopalladate anions apparently undergo SN2‐type reactions with the AlkylX coupling partner. The resulting neutral complexes then release the cross‐coupling products by reductive elimination. In gas‐phase fragmentation experiments, the occurrence of reductive eliminations was observed for anionic analogues of the neutral complexes. Although the actual catalytic cycle is supposed to involve chiefly mononuclear palladium species, anionic palladium nanoclusters [PdnR(DE)n]−, (n=2, 4, 6; DE=diene) were also observed. At short reaction times, the dinuclear complexes usually predominated, whereas at longer times the tetra‐ and hexanuclear clusters became relatively more abundant. In parallel, the formation of palladium black pointed to continued aggregation processes. Thus, the present study directly shows dynamic behavior of the palladium/diene catalyst system and degradation of the active catalyst with increasing reaction time.

“…The handful of organosilver(III) compounds currently known are only stabilized by either macrocyclic ligands or by fluorinated methyl groups . In fact, the non‐fluorinated complexes [(CH 3 ) 3 AgI] − and [(CH 3 ) 4 Ag] − were found to be unstable . On the other hand, aside from the paramagnetic phase Cs 2 KAgF 6 , the known silver(III) fluorides are restricted to the binary compound AgF 3 and a number of salts of its diamagnetic [AgF 4 ] − complex anion .…”

Section: Methodsmentioning

confidence: 99%

“…This is also at variance with the recently reported oxidative addition of CH 3 I to the non‐fluorinated complex [CH 3 AgCH 3 ] − , which resulted in the highly unstable [(CH 3 ) 3 AgI] − . The latter compound was detected (NMR and MS) but not isolated …”

Section: Methodsmentioning

confidence: 99%

The First Organosilver(III) Fluoride, [PPh₄][(CF₃)₃AgF]

Joven-Sancho

Baya

Martín

et al. 2020

Organosilver(III) fluoride complexes have been assigned a key role in different fluorination processes. To the best of our knowledge, however, none of them seem to have been isolated or even detected thus far. Here we report on the successful synthesis of the trifluoromethyl derivative [PPh4][(CF3)3AgF], which has been isolated in high yield. The thermodynamic stability of the Ag−F bond is shown by calculation and demonstrated by multistage mass spectrometry (MSn) under collision‐induced dissociation (CID) conditions. Nevertheless, the substantial elongation found in the Ag−F bond (X‐ray) is correlated with a marked nucleophilic character of the terminal F ligand. This Ag−F bond is, in fact, quite reactive: it suffers hydrolysis and is also solvolyzed by thiols.