17171-73-2Relevant academic research and scientific papers
Two flavors of PEPPSI-IPr: Activation and diffusion control in a single NHC-ligated Pd catalyst?
Larrosa, Igor,Somoza, Clara,Banquy, Alexandre,Goldup, Stephen M.
supporting information; experimental part, p. 146 - 149 (2011/03/20)
Abnormal reactivity has been observed in Negishi, Suzuki-Miyaura, and Kumada-Tamao-Corriu cross-couplings in which PEPPSI-IPr (where PEPPSI stands for pyridine enhanced precatalyst preparation, stabilization, and initiation and IPr refers to the NHC ligand) is employed, implicating the presence of two distinct Pd0 species in the catalytic cycle. Polybrominated arenes and organometallic reagents react selectively to give the product of exhaustive polysubstitution regardless of the initial reaction stoichiometry. Competition experiments suggest that, after an initial activation controlled oxidative addition, reductive elimination produces an ultrareactive Pd0 species which consumes all remaining C-Br bonds in the molecule under diffusion control.
Synthesis and spectroscopic study of hexadecaalkyl-substituted rare-earth diphthalocyanines
Pushkarev,Ivanov,Zhukov,Shulishov,Tomilov
, p. 554 - 560 (2007/10/03)
New hexadecaalkyl-substituted diphthalocyanine complexes of lanthanides RPc2Ln (R = Et, or Bu; Ln = Lu, Dy, or Eu) were synthesized by three methods: in solution in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, in a melt of a m
Synthesis of Diacetylene Macrocycles Derived from 1,2-Diethynylbenzene Derivatives: Structure and Reactivity of the Strained Cyclic Dimer
Zhou, Qin,Carroll, Patrick J.,Swager, Timothy M.
, p. 1294 - 1301 (2007/10/02)
Diacetylene macrocycles 2-4 (n=1-3) (R=H, C4H9, C6H13, C10H21, C12H25, OC10H21) have been prepared from the oxidative coupling of 1,2-diethynylbenzene derivatives.These compounds can be produced in useful quantities and are of interest as precursors to novel conjugated organic polymers.The reported results indicate that when the R groups are large the dimeric macrocycle (n=1) can be prepared in as high as 74percent yield from the corresponding 1,2-diethynylbenzene in a one-step procedure.An alternate multistep procedure was found to produce the tetrameric macrocycle (n=3,R=C6H13) in 45percent yield.The highly strained dimeric macrocycle was characterized by an X-ray structure and was found to be very reactive.The dimers undergo a rapid very exothermic polymerization at 100-125 deg C, indicative of a chain reaction.Reaction of the dimeric macrocycles with iodine results in intramolecular cyclization and a new 20? electron tetraiodide fused ring system.Reaction of the tetraiodide with oxygen produces a related compound in which two of the iodides have been converted to ketones.
METALATION REACTIONS. VII. METALATION OF BENZYLALKYL AND β-PHENETHYLALKYL SULFIDES
Cabiddu, S.,Floris, C.,Melis, S.,Piras, P. P.,Sotgiu, F.
, p. 149 - 156 (2007/10/02)
The products from the reaction between n-butyllithium and benzylalkyl and β-phenethylalkyl sulfides followed by carbonation, have been investigated by GLC/MS analysis.With benzylalkyl sulfides metalation occurs at the benzylic position, and the corresponding carboxylic acid can be isolated, but side products from Wittig like rearrangement, cleavage of the thioether bond, and aliphatic and aromatic substitution are also obtained.No benzylic metalation or Wittig-like rearrangement products are obtained from β-phenethyl sulfides: instead cleavage of the thioether bond and aliphatic and aromatic substitution occur.
SELECTIVE MONO-ALKYLATION AND ARYLATION OF AROMATIC DIHALIDES BY PALLADIUM-CATALYZED CROSS-COUPLING WITH THE GRIGNARD AND ORGANOZINC REAGENTS
Minato, Akio,Tamao, Kohei,Hayashi, Tamio,Suzuki, Keizo,Kumada, Makoto
, p. 845 - 848 (2007/10/02)
Dibromobenzene, dibromothiophenes, dichloro- and dibromopyridine are highly selectively mono-alkylated and arylated with Grignard or organozinc reagents in the presence of palladium complexes as catalysts.
