53253-08-0Relevant academic research and scientific papers
Catalytic intermolecular Pauson-Khand-type reaction: Strong directing effect of pyridylsilyl and pyrimidylsilyl groups and isolation of Ru complexes relevant to catalytic reaction
Itami, Kenichiro,Mitsudo, Koichi,Fujita, Kazuyoshi,Ohashi, Youichi,Yoshida, Jun-Ichi
, p. 11058 - 11066 (2007/10/03)
Some circumstantial evidence for the directing effect of the 2-pyhdylsilyl group in the Ru-catalyzed intermolecular Pauson-Khand-type reaction (PKR) of alkenyl(2-pyridyl)silane, alkyne, and carbon monoxide has been provided. Most importantly, we have succeeded in isolating several monometallic Ru complexes relevant to the catalytic reaction: Ru(vinylsilane)(CO)3 complexes and ruthenacyclopentene. While the stoichimetric reaction of the Ru(vinylsilane)(CO)3 complex with an alkyne led to the formation of the corresponding cyclopentenone (PKR product) at 100 °C, the ruthenacyclopentene intermediate was quantitatively produced at 50 °C. This complex was also converted to a cyclopentenone upon heating at 100 °C. Moreover, it was also found that the Ru(vinylsilane)(CO)3 complex and ruthenacyclopentene serve as catalysts in intermolecular PKR.
A pyridylsilyl group expands the scope of catalytic intermolecular Pauson-Khand reactions
Itami, Kenichiro,Mitsudo, Koichi,Yoshida, Jun-Ichi
, p. 3481 - 3484 (2007/10/03)
Now even unstrained alkenes can be used in catalytic intermolecular Pauson-Khand reactions [Eq. (a)]. This is made possible by the use of the directing group dimethyl(2-pyridyl)silyl, which can be easily removed at the end of the reaction. Furthermore, one observes completely regioselective incorporation of substituents at the 4- and 5-positions of the 2-cyclopentenone structure.
Process for preparing cyclopentenone derivatives
-
, (2008/06/13)
A novel and industrial process for preparing cyclopentenone derivatives by heating C5 ?C13 aliphatic acids having one substituent or intramolecular esters thereof in the presence of a solid acid catalyst in a good yield.
