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Air- and moisture-stable nickel(II) and palladium(II) complexes from phebox pincer ligands 1− 5have been synthesized, and their Lewis activity was investigated. 2,6-Bis(oxazolinyl)phenylnickel halide complexes [NiX(phebox)] and 2,6-bis(oxazolinyl)phenylpalladium halide complexes [PdX(phebox)] were synthesized via oxidative addition with [Ni(COD) 2] or Pd 2dba 3, respectively, followed by halide abstraction using silver(I) salts to form complexes such as [Ni(phebox)][ClO 4] ( 41). Herein, X-ray crystal structures are reported for several pincer complexes having the expected square-planar geometries with the terdentate NCN pincer system. Complexes with general structure [M(phebox)]X where X is a halogen showed no relative Lewis acidity. On the other hand, complexes where X was exchanged for a less coordinating counterion showed increased Lewis acidity. The relative Lewis acidity varies depending on the substituents on the benzene core of the pincer ligands, due to the electronic effects of the ligand on the metal center. [ABSTRACT FROM AUTHOR]

A catalytic amount of RuHCl(CO)(PCy 3) 2( 1) activated with AgOTF or AgSbF 6at room temperature was found to be an effective catalyst system for the hydrovinylation of vinylarenes. Vinylarenes with both electron-donating and electron-withdrawing substituents reacted with ethylene at room temperature to provide the desired 3-arylbutenes in moderate to excellent yield (60−99%) under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Reactive nitrones can be generated directly in situ by an unusual reaction of nitrosobenzene with styrene. [ABSTRACT FROM AUTHOR]