NCN pincer palladium complexes based on 1,3-dipicolyl-3,4,5,6-tetrahydropyrimidin-2-ylidenes: synthesis, characterization and catalytic activities

Yang, Liangru; Zhang, Xinchi; Mao, Pu; Xiao, Yihong; Bian, Huanyu; Yuan, Jun; Mai, Wenpeng; Qu, Lingbo

doi:10.1039/c5ra01706h

Cited by 19 publications

(5 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Subsequently, two NCN pincer ring-expanded sixmembered NHCepalladium complexes containing 1,3dipicolyl-3,4,5,6-tetrahydropyrimidin-2-ylidenes have been synthesized by the direct metalation of the corresponding tetrahydropyridin-1-ium salts [79]. Catalytic activity study showed that the complexes catalyzed the Heck reaction of aryl bromides with acrylate/styrene efficiently using Et 3 N as base and DMA as a solvent.…”

Section: Mizorokieheck Reactionmentioning

confidence: 99%

Palladium–N-heterocyclic carbene complexes for the Mizoroki–Heck reaction: An appraisal

Balinge¹,

Bhagat²

2017

Comptes Rendus. Chimie

View full text Add to dashboard Cite

This article presents a review of the most significant developments with N-heterocyclic carbene (NHC)epalladium catalytic systems used for the Heck reaction. For more than the past two decades, a large number of new NHCePd complexes have been synthesized and characterized. These studies focused on NHCs as a phosphine analogue, but the current review highlights the differences with particular ligands so as to attain a suitable balance between the electronic and bulky environments around the metal. NHCs have gained wide recognition as these ligands act as excellent s-donors that form stable metaleNHCs with strong metalecarbon bonds. For this reason, metaleNHCs are commonly used as they are highly reactive and can selectively serve as catalysts for various chemical transformations. The objective of our article is to highlight significant recent progress in NHCePd(II) complexes and provide an overview of their extensive interaction in the MizorokieHeck reaction.

show abstract

Section: Mizorokieheck Reactionmentioning

confidence: 99%

Palladium–N-heterocyclic carbene complexes for the Mizoroki–Heck reaction: An appraisal

Balinge¹,

Bhagat²

2017

Comptes Rendus. Chimie

View full text Add to dashboard Cite

show abstract

“…112 NHC-PdCl 2 (pyridine) complexes (C78a-f ) for the coupling of various aryl chlorides under mild condi-tions in aqueous DMF with low catalyst loadings (0.01 mol%) resulted in high yields (Table 8, entries 44-47). 113 The complexes C79 were applied in the reaction of phenylboronic acid with aryl halides in neat water, the complexes 79b and 79d displayed the highest catalytic activity at 100 • C (Table 8, entries [48][49][50][51], and the catalytic system could be reused several times with only a slight decrease in its activity. Water-soluble Pd(II)-NHC complex, C80, where NHC is a dianionic sulfonated and sterically hindered catalyst, was used for the Suzuki coupling of aryl chlorides and boronic acids in mixtures i PrOH/water or water (Table 8, entries 52-55).…”

Section: Biphasic Catalysismentioning

confidence: 99%

“…• C (Table 8, entries [48][49][50][51], and the catalytic system could be reused several times with only a slight decrease in its activity. 114 Water-soluble Pd(II)-NHC complex, C80, where NHC is a dianionic sulfonated and sterically hindered catalyst, was used for the Suzuki coupling of aryl chlorides and boronic acids in mixtures i PrOH/water or water (Table 8, entries 52-55).…”

mentioning

confidence: 99%

Cross coupling reactions catalyzed by (NHC)Pd(II) complexes

Gürbüz¹,

Karaca²,

Özdemır³

et al. 2015

Turk J Chem

View full text Add to dashboard Cite

This review is focused on new developments reported during the last 3 years concerning the catalytic performances of in situ formed or preformed NHC-Pd(II) complexes (NHC: N -heterocyclic carbene) for cross-coupling reactions such as Heck-Mizoraki (often shortened to the Heck reaction), Kumada, Negishi, Suzuki-Miyaura (often shortened to the Suzuki reaction), Sonogashira and Hiyama couplings, and the Buchwald-Hartwig aminations, which are extremely powerful in the formation of C-C and C-heteroatom bonds. Due to the great number of publications and limited space here, we made a special attempt to compile the relevant data in tables, which we hope will serve as a guide for chemists interested in these reactions. The syntheses of the precatalysts and the generally accepted reaction mechanisms are also briefly described.

show abstract

“…Complexes B on the other hand were the product of targeted, modular synthesis (M = Cr, Fe). , Iron derivatives in particular were extensively investigated, and the strongly electron-donating ligand proved to be capable to stabilize complexes having the metal in formal oxidation states 0, I, II, and III. , Some of these iron complexes were shown to be proficient at promoting lactide polymerization . The photophysical properties of derivatives C (M = Ru, Pd, Pt) have been discussed, while palladium derivatives D have shown catalytic activity toward Heck coupling . Pincer complexes E , (M = Ni, Rh, Ir) incorporating a polycyclic, chiral backbone derived from (1 R )-camphor have been investigated as catalysts for hydrogenation and transfer hydrogenation reactions .…”

Section: Introductionmentioning

confidence: 99%

“…9c The photophysical properties of derivatives C (M = Ru, Pd, Pt) have been discussed, 10 while palladium derivatives D have shown catalytic activity toward Heck coupling. 11 Pincer complexes E, (M = Ni, Rh, Ir) incorporating a polycyclic, chiral backbone derived from (1R)-camphor have been investigated as catalysts for hydrogenation and transfer hydrogenation reactions. 12 Only two types of PCP pincer ligands incorporating six-membered NHCs in the central positions have been reported to date.…”

Section: ■ Introductionmentioning

confidence: 99%

Nickel, Ruthenium, and Rhodium NCN-Pincer Complexes Featuring a Six-Membered N-Heterocyclic Carbene Central Moiety and Pyridyl Pendant Arms

2018

View full text Add to dashboard Cite

NCN pincer ligand precursor 1•HX (X = Cl, PF 6 ), having a six-membered N-heterocyclic carbene central moiety and pyridyl pendant arms, was prepared via N−C crosscoupling of 2-bromo-6-tert-butylpyridine with propane-1,3diamine, followed by ring closure with triethylorthoformate. The free ligand 1 was not accessible via deprotonation, yet its copper(I) complex 2 was prepared by reacting 1•HCl with CuI and potassium hexamethyldisilazide. It was used further as a transmetalation agent to prepare nickel(II) and ruthenium(II) dihalide NCN-pincer complexes 3a, 4a, and 4b, featuring a distorted square-pyramidal geometry at the metal, with the carbene ligand in the axial position. The rhodium(III) NCNpincer complex 6b was obtained from 2 and [Rh(cod)Cl] 2 via transmetalation followed by oxidation with Cu(I) in THF. The rhodium(III) NCC-pincer complex 9b was prepared under similar conditions in acetonitrile, where a spontaneous rollover cyclometalation occurred. Complex 9b has a distorted octahedral geometry, with the acetonitrile ligand trans to the carbene. Very short Ru−C NHC and Rh−C NHC bonds were measured in complexes 4a, 4b, and 9b. Halogen exchange was observed by 1 H and 13 C NMR spectroscopy in both ruthenium and rhodium systems during the transmetalation stage, and the purification was accomplished by pushing the respective equilibrium with excess halide.

show abstract

NCN pincer palladium complexes based on 1,3-dipicolyl-3,4,5,6-tetrahydropyrimidin-2-ylidenes: synthesis, characterization and catalytic activities

Abstract: NCN pincer six-membered NHC palladium complexes were synthesized, characterized and used in Heck reaction of aryl bromides with olefines.

Cited by 19 publications

References 82 publications

Palladium–N-heterocyclic carbene complexes for the Mizoroki–Heck reaction: An appraisal

Palladium–N-heterocyclic carbene complexes for the Mizoroki–Heck reaction: An appraisal

Cross coupling reactions catalyzed by (NHC)Pd(II) complexes

Nickel, Ruthenium, and Rhodium NCN-Pincer Complexes Featuring a Six-Membered N-Heterocyclic Carbene Central Moiety and Pyridyl Pendant Arms

Contact Info

Product

Resources

About