2‐hydroxyethyl‐substituted (NHC)PdI₂(pyridine) (Pd‐PEPPSI) Complexes: Synthesis, Characterization and the Catalytic Activity in the Sonogashira Cross‐coupling Reaction

Abstract

Here, new series of the 2‐hydroxyethyl‐substituted (NHC)PdI2(pyridine) (Pd‐PEPPSI) complexes have been synthesized. These complexes have been prepared from the 2‐hydroxyethyl‐substituted N‐heterocyclic carbene (NHC) precursors, palladium chloride and pyridine. The synthesized Pd‐PEPPSI complexes have been characterized by using 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. The catalytic activity of the 2‐hydroxyethyl‐substituted Pd‐PEPPSI complexes has been examined in the Sonogashira cross‐coupling reaction by using phenylacetylene and aryl bromide. The Pd‐PEPPSI complexes have demonstrated great activity in the Sonogashira cross‐coupling reaction. The molecular and crystal structures of the three of the Pd‐PEPPSI complexes were determined by single‐crystal X‐ray diffraction method. X‐ray studies show that all the molecular structures adopt slightly distorted square‐planar geometry around the palladium (II) center.

New PEPPSI‐Pd‐NHC complexes bearing 4‐hydroxyphenylethyl group: Synthesis, characterization, molecular docking, and bioactivity properties

“…The final product was obtained as a yellow solid. [ 10–12 ] Yield: 71% (425 mg); m.p. : 168–169°C; ν (CN) : 1446 cm −1 ; ν (O–H) : 3351 cm −1 .…”

“…[2,8,9] In various catalytic systems described in the literature, significant progress has been made in different cross-linking reactions using pyridine enhanced, precatalyst, preparation, stabilization, and initiation (PEPPSI)-Pd-NHC complexes and these complexes have been reported to be highly efficient catalysts. [10][11][12][13][14][15] One of the most appealing properties of PEPPSI-Pd-NHC complexes in these studies is their stability in reaction environments under ambient conditions. [16] In the last decade, studies on the biological activities of the Pd-NHC complexes such as antileishmanial, [17] antibacterial, [17,18] antimicrobial, [18] and antitumor agents [19] have been published.…”

Design, Synthesis, Characterization and Catalytic Activity in Direct Arylation Reaction of the Benzimidazole-Functionalized PEPPSI-type Pd(II)NHC Complexes bearing 4-Vynylbenzyl Group

“…Tüm spektroskopik sonuçlar, diğer PEPPSI tipi Pd(II)NHC kompleksleri için elde edilenlerle uyumludur. (Aktaş, Barut Celepci, Gök & M. Aygün, 2018;Daşgın et al, 2021;Erdemir, Barut Celepci, Aktaş & Gök, 2019;Roger, Pozgan & Doucet, 2009;Slimani, Mansour, Özdemir, Gürbüz & Hamdi, 2021;Türker et al, 2020) Şema 1. 4-vinilbenzil grubu 1a-e taşıyan PEPPSI tipi Pd(II)NHC komplekslerinin sentezi.…”

“…(Organ, Chass, Fang, Hopkinson & Valente, 2008), bu komplekslerin farklı katalitik aktiviteleri üzerine araştırmaların artmasına neden oldu. (Boztepe, Künkül & Gürbüz, 2020;Gokanapalli, Motakatla & Peddiahgari, 2020;Jiao et al, 2020;Reddy, Anusha & Reddy, (2020) Šimůnek, Rybáčková, Svoboda & Kvíčala, 2020;Yingying et al, 2020) Son çalışmalar, Pd(II)NHC komplekslerinin Sonogashira, (Erdemir, Barut Celepci, Aktaş & Gök, 2019). Suzuki-Miyaura, (Aktaş, Barut Celepci, Gök & Aygün, 2018) Mizoroki-Heck (Borah, Saha, Sarma & Das, 2020;İmik, Yaşar & Özdemir, 2019) ve doğrudan arilasyon reaksiyonları gibi C-C birleştirme reaksiyonları için etkili katalizörler olarak çalışabileceğini göstermektedir.…”

Sonogashira-Hagihara and Buchwald-Hartwig cross-coupling reactions with sydnone and sydnone imine derived catalysts

“…8 Early reports deal with di(imidazol-1-yl-2-ylidene)methane, 9 2-(imidazol-1-yl-2-ylidene)methyl)pyridine 10 and bis(1,3-di-Ntert-butylimidazol-2-ylidene) Pd complexes 11 as catalysts. Since then considerable progress has been made with respect to new and effective NHCs, [12][13][14] abnormal NHCs, 15 and polymer-supported NHC catalysts in Sonogashira-Hagihara cross-couplings. 16 The application of N-heterocyclic carbenes in Buchwald-Hartwig cross-couplings is well-established.…”