16971-33-8Relevant articles and documents
Detection and Structural Investigation of Elusive Palladium Hydride Intermediates Formed from Simple Metal Salts
Kostyukovich, Alexander Yu.,Burykina, Julia V.,Eremin, Dmitry B.,Ananikov, Valentine P.
, p. 7128 - 7142 (2021/05/26)
The Mizoroki-Heck reaction is one of the most known and best studied catalytic transformations and has provided an outstanding driving force for the development of catalysis and synthetic applications. Three out of four classical Mizoroki-Heck catalytic cycle intermediates contain Pd-C bonds and are well known and studied in detail. However, a simple palladium hydride (which is formed after the product-releasing β-H-elimination step) is a kind of elusive intermediate in the Mizoroki-Heck reaction. In the present study, we performed a combined theoretical and mass spectrometry (MS) study of palladium hydride complexes [PdX2H]- (X = Cl, Br, and I), which are reactive intermediates in the Mizoroki-Heck reaction. Static and molecular dynamic calculations revealed that these species have a T-shaped structure with a trans-arrangement of halogen atoms. Other isomers of [PdX2H]- are unstable and easily rearrange into the T-shaped form or decompose. These palladium hydride intermediates were detected by MS in precatalyst activation using NaBH4, Et3N, and a solvent molecule as reducing agents. Online MS monitoring allowed the detection of [PdX2H]- species in the course of the Mizoroki-Heck reaction.
Preparation and Reactivity of Mixed-Ligands Hydride Complexes [RuHCl(CO)(PPh3)2{P(OR)3}]
Albertin, Gabriele,Antoniutti, Stefano,Castro, Jesús
, p. 688 - 693 (2019/05/10)
Mixed-ligands hydride complexes [RuHCl(CO)(PPh3)2{P(OR)3}] (2) (R = Me, Et) were prepared by allowing [RuHCl(CO)(PPh3)3] (1) to react with an excess of phosphites P(OR)3 in refluxing benzene. Treatment of hydrides 2 first with triflic acid and next with an excess of hydrazine afforded hydrazine complexes [RuCl(CO)(κ1-NH2NHR1)(PPh3)2{P(OR)3}]BPh4 (3, 4) (R1 = H, CH3). Diethylcyanamide derivatives [RuCl(CO)(N≡CNEt2)(PPh3)2{P(OR)3}]BPh4 (5) were also prepared by reacting 2 first with HOTf and then with N≡CNEt2. The complexes were characterized spectroscopically and by X-ray crystal structure determination of [RuHCl(CO)(PPh3)2{P(OEt)3}] (2b).
Palladium-Catalyzed Direct Intramolecular C-N Bond Formation: Access to Multisubstituted Dihydropyrroles
Jiang, Bing,Meng, Fei-Fan,Liang, Qiu-Ju,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 914 - 917 (2017/02/26)
A palladium-catalyzed intramolecular amination of alkenes with retention of olefin functionalization was achieved under mild reaction conditions. In the presence of palladium catalyst, the tosyl-protected amine can directly couple with a double bond to provide versatile dihydropyrrole derivatives in moderate to excellent yields.
