Copper-Catalyzed Ring-Opening of Heterobicyclic Alkenes with Grignard Reagents: Remarkably High<i>anti</i>-Stereocontrol
作者:Ramón Gómez Arrayás、Juan Carlos Carretero、Silvia Cabrera
DOI:10.1055/s-2006-926379
日期:——
protocols for the ring-opening reaction of heterobicyclic alkenes with carbon nucleophiles which typically occur with syn selectivity, the alkylative ring-opening reaction of [2.2.1]oxa- and azabicyclicalkenes with Grignard reagents in the presence of a catalytic amount of copper(I) takes place with very high or complete anti-stereocontrol under smooth reaction conditions. This new procedure proved to
Cationic Pd<sup> <i>II</i> </sup> Complexes of Fesulphos Ligands: Highly Efficient Catalysts for the Enantioselective Ring Opening of Oxa- and Azabicyclic Alkenes with Dialkylzinc Reagents
作者:Silvia Cabrera、Inés Alonso、Ramón Gómez Arrayás、Olga Familiar、Juan C. Carretero
DOI:10.1080/10426500590913474
日期:2005.3.2
The Pd-catalyzed enantioselective ring-opening reaction of meso oxaand azabicyclic alkenes with dialkylzinc reagents reported by Lautens et al.1 constitutes a synthetically outstanding C C bond-forming desymmetrization reaction. Herein we describe that cationic methyl PdII complexes of Fesulphos ligands2 serve as excellent catalysts for this asymmetric transformation, allowing the performance of the
Optically active dinuclear palladium complexes containing a Pd−Pd bond were prepared by using (R,R)-bis(tert-butylmethylphosphino)methane ((R,R)-t-Bu-MiniPHOS). The dinuclear palladium complexes coupled with silver triflate exhibited good to excellent enantioselectivities up to 99% in palladium-catalyzed alkylative ring-openingreactions of azabenzonorbornadienes.