Cyclopalladated Compounds with Polyhalogenated Benzylphosphanes for the Mizoroki‐Heck Reaction. Issue 25 (9th June 2020)

• Record Type: Journal Article
• Authors: López‐Mosquera, Cristina; Grabulosa, Arnald; Rocamora, Mercè; Font‐Bardia, Mercè; Muller, Guillermo
• Is Part Of: European journal of inorganic chemistry. Issue 25(2020)
• Page Start: 2470
• Page End: 2484
• Publication Date: 2020-06-09
• Subjects: Phosphane ligands -- Palladium -- Heck reaction; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.202000288
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : Nine partially halogenated benzylphosphanes ArX CH2 PR2 (ArX = 3, 6‐dichlorophenyl, 3, 6‐difluorophenyl and 3, 4, 5‐trifluorophenyl; R = Ph, Cy, i Pr) have been prepared and reacted with palladium acetate to obtain the cyclometallated dimers [Pd( µ ‐OAc)(κ 2 ‐ C, P ‐ArX CH2 PR2 )]2 . The acetate bridge has been exchanged by bromide using lithium bromide and the obtained dimers have been thoroughly characterised. The dimers with the non‐halogenated phosphanes PhCH2 PR2 (R = Ph, i Pr) have also been prepared. Treatment with norbornadiene in the presence of silver tetrafluoroborate has furnished the cationic mononuclear complexes [Pd(κ 2 ‐ C, P ‐ArX CH2 PR2 )(nbd)]BF4 as stable solids. These complexes and some of the bromide dimers have been used as catalytic precursors in the Mizoroki‐Heck reaction between bromobenzene and butyl acrylate. The complexes efficiently catalyse this transformation and important differences of activity are found depending on the ligand. In general, fluorinated phosphanes give more active systems than chlorinated analogues. Abstract : The synthesis of halogenated benzylphosphanes and their cyclopalladated compounds is described along with the use of the complexes in the Mizoroki‐Heck reaction.