Rhodium(i) complexes with proton-responsive anionic tethered N-heterocyclic carbene ligands: synthesis and application in alkyne dimerization
Küçük Resim Yok
Tarih
2025
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Royal Soc Chemistry
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
A series of rhodium(i) complexes of formula Rh{kappa 2C,X-(IDippR)}(cod) and Rh{kappa 2C,X-(IDippR)}(CO)2 {IDippR = 1-(R)-3-(2,6-diisopropylphenyl)-imidazolin-2-carbene; X = N, O; R = (6-yl-2-pyridone), (CH2CH2NC( 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 O)Ph), (CH2CH2COO); (cod = 1,5-cyclooctadiene)} containing anionic-tethered NHC-functionalized ligands, including pyridonato, amidato or carboxylato groups at the N-wingtip, has been prepared and their application to alkyne homocoupling has been investigated. The chelate coordination of the NHC-functionalized ligand generates 5, 6 and 7-membered metallacycles for pyridonato, amidato and carboxylato substituents, respectively. Preparation of the mixed bis-NHC derivative Rh{kappa 2C,O-(IDippCarbx)}(CO)(IPr) {IPr = 1,3-bis-(2,6-diisopropylphenyl)-imidazolin-2-carbene} is possible due to lability of one of the CO ligands in the bis-CO precursor. Reversible protonation is observed for pyridonato and carboxylato moieties but not for amidato counterpart. Alkyne dimerization catalytic activity is reported for N-based anionic groups whereas carboxylato counterparts are inefficient. A proton transfer mechanism is invoked for the gem-selectivity observed for cod-based catalysts whereas alkyne insertion is the regioselectivity-determining step for CO-containing analogues.
Açıklama
Anahtar Kelimeler
To-Tail Dimerization, Terminal Alkynes, Metal-Complexes, Nhc Ligands, Catalysts, Iridium, Bond, Reactivity, Carbopalladation, Hydrogenation
Kaynak
Dalton Transactions
WoS Q Değeri
Q1
Scopus Q Değeri
Q2
Cilt
54
Sayı
40
