216392-11-9Relevant academic research and scientific papers
Acceleration effect of an allylic hydroxy group on ring-closing enyne metathesis of terminal alkynes: Scope, application, and mechanistic insights
Imahori, Tatsushi,Ojima, Hidetomo,Yoshimura, Yuichi,Takahata, Hiroki
experimental part, p. 10762 - 10771 (2009/12/01)
An interesting acceleration effect of an allylic hydroxy group on ring-closing enyne metathesis has been found. Ring-closing enyne metathesis of terminal alkynes possessing an allylic hydroxy group proceeded smoothly without the ethylene atmosphere generally necessary to promote the reaction. The synthesis of (+)-isofagomine with the aid of this efficient reaction has been demonstrated. Mechanistic studies of the acceleration effect were also carried out. Results of NMR studies suggested that the reaction proceeded via an "ene-then-yne" pathway. Kinetic studies indicated switching of the rate-determining step as a consequence of the presence of an allylic hydroxy group. These results suggest acceleration of the reentry step of Ru-carbene species by the allylic hydroxy group.
Enantioselective Diels-Alder cycloadditions with (SS)-2-(p- tolylsulfinyl)-1,4-naphthoquinone: Efficient kinetic resolution of chiral racemic vinylcyclohexenes
Carreno, M. Carmen,Urbano, Antonio,Di Vitta, Claudio
, p. 8320 - 8330 (2007/10/03)
Chiral racemic vinylcyclohexenes 1a-m, bearing allylic and nonallylic oxygenated substituents on the cyclohexene ring, were submitted to Diels- Alder reactions with enantiomerically pure (SS)-(2-p-tolylsulfinyl)-1,4- naphthoquinone. The tandem cycloadditi
