Intermediates in the Palladium-Catalysed Reactions of 1,3-Dienes, Part 5 [1] Butadiene Complexes of Nickel, Palladium and Platinum

Abstract

<jats:p>A series of [M(R<jats:sub>2</jats:sub>PC<jats:sub>2</jats:sub>H<jats:sub>4</jats:sub>PR<jats:sub>2</jats:sub>)(butadiene)] complexes of Ni, Pd and Pt has been prepared and their structures investigated NMR-spectroscopically. The nickel and palladium complexes, irre­spective of the substituents at phosphorus, contain a fluxional η<jats:sup>2</jats:sup>-bonded butadiene molecule. In the case of platinum the bonding mode is ligand dependent: an η<jats:sup>2</jats:sup>-arrangement is observed where R is tert-butyl or cyclohexyl while when R is isopropyl the butadiene adopts an η<jats:sup>1</jats:sup>, η<jats:sup>1</jats:sup>-arrangement to give a platinacyclopentene derivative. </jats:p>

The First Catalytic Synthesis of an Acrylate from CO2 and an Alkene—A Rational Approach

“…Mass spectra were recorded on a Finnigan LCQ with a quadrupole ion trap (positive ion channel). Bis(di‐ tert ‐butylphosphino)ethane45 and bis(di‐ tert ‐butylphosphino)propane46 were synthesized by following reported procedures. X‐ray structures were solved by direct methods and refined against F 2 with a full‐matrix least‐squares algorithm by using the SHELXTL (Version 2008/4) software package‐47 Intensities were corrected for Lorentz and polarization effects 48…”

Telomerization: Advances and Applications of a Versatile Reaction

“…The first is the monopalladium bisallyl mechanism (Scheme 1) based on results found by Jolly et al [4][5][6][7][8] Some intermediates involved in this mechanism were isolated for the reaction of butadiene with methanol. After removal of n ligands and oxidative coupling of two molecules of 1,3-butadiene the [Pd II ( 1 h-3 h-octadiendiyl)] complex is formed (steps 1 and 2).…”

“…This effect is also observed when [Pd(C 3 H 5 )(cod)]BF 4 (cod = cyclooctadiene) was used as a precursor instead of PdCl 2 . The reaction profile significantly changed when tris(2,4,6-trimethoxyphenyl)phosphine (P[Ph(OMe) 3 ] 3 ) was used as a ligand in combination with [Pd(C 3 H 5 )(cod)]BF 4 . A dramatic increase in selectivity towards the head-to-head telomers was observed forced by the great cone angle of the ligand of 1848.…”

Telomerisation – Fortschritte und Anwendungen einer vielseitigen Reaktion

“…Der erste ist der Monopalladium-Bisallyl-Mechanismus, der auf Befunden von Jolly et al [4][5][6][7][8] basiert (Schema 1). Einige Intermediate dieses Mechanismus konnten bei der Reaktion von Butadien mit Methanol isoliert werden.…”

“…Durch den Einsatz sehr geringer Katalysatorkonzentrationen konnten sehr hohe TONs erreicht werden. 4 ] untersucht. Hauptsächlich wurde bei der Optimierung das P/PdVerhältnis des polaren Katalysatorsystems mit TPPMS und TPPTS betrachtet.…”