53952-94-6Relevant 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
supporting information; 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.
Catalytic one-pot synthesis of cyclic amidines by virtue of tandem reactions involving intramolecular hydroamination under mild conditions
Chang, Sukbok,Lee, Minjae,Jung, Doo Young,Yoo, Eun Jeong,Cho, Seung Hwan,Han, Sun Kyu
, p. 12366 - 12367 (2007/10/03)
A new synthetic methodology for the generation of cyclic amidines has been developed by the reaction of 1,n-aminoalkynes with electron-deficient azides using a ruthenium catalyst at ambient temperature. The reaction proceeds most likely via a tandem sequence of intramolecular hydroamination of aminoalkynes, cycloaddition of azides with the resulting enamines, and rearrangement of triazoline intermediates. It demonstrates, as the proof-of-principle, that an equilibria cascade sequence can be favorably driven by an irreversible step, thus enabling a facile one-pot synthetic route to deliver molecular complexity under unprecedented mild conditions without relying on the traditional linear approaches. Copyright
