Radical Germylzincation of α-Heteroatom-Substituted Alkynes

Synthesis of heteroatom-substituted analogues of stearic acid.

We report herein the syntheses of several analogues of stearic acid in which oxygen or sulfur atoms or sulfoxide groups have replaced the methylene groups at either position 9 or position 10 of the polymethylene chains. These compounds have been fully characterized by the results of proton and carbon 13 nuclear magnetic resonance, and low and high resolution mass spectral studies.

Heteroatom-Substituted Delaminated Zeolites as Solid Lewis-Acid Catalysts

Nickel-catalyzed decarbonylative alkylidenation of phthalimides with trimethylsilyl-substituted alkynes.

We have developed a nickel-catalyzed transformation, in which phthalimides react with trimethylsilyl-substituted alkynes in the presence of Ni(0)/PMe3/MAD catalyst to provide isoindolinones. The reaction process displays an unusual mechanistic feature-decarbonylation and alkylidenation. The use of both trimethylsilyl-substiuted alkynes and MAD was found to be essential for the transformation wi...

Asymmetric intermolecular Pauson-Khand reaction of symmetrically substituted alkynes.

The asymmetric intermolecular Pauson-Khand reaction of symmetric alkynes has been accomplished for the first time. N-Phosphino-p-tolylsulfinamide (PNSO) ligands have been identified as efficient ligands in this process. The chirality of the cobalt S-bonded sulfinyl moiety was found to direct olefin insertion into one of the two possible cobalt-carbon bonds in the alkyne complex. Reaction of sym...

Addition reactions of heteroatom - COX ( X = OR , NR 2 , COOR ) species with alkynes *

Heteroatom-COX species where the heteroatom is Cl, S, or Sn and X is alkoxy, amino, or alkoxycarbonyl group were found to add to the triple bond of alkynes regioand stereoselectively in the presence of Rh, Pd, or Ni catalyst. Scope and limitation of these synthetic reactions were disclosed. Mechanistic study revealed that oxidative addition of these heteroatom-COX bonds readily took place and t...