ja035424i_si_001.txt (20.77 kB)
η3-Pyranyl and η3-Pyridinyl Molybdenum π-Complexes as Chiral Scaffolds for the Enantioselective Construction of Substituted Oxa- and Aza[3.3.1]bicyclics: First Enantio- and Regiocontrolled [5+3] Cycloaddition Reactions
datasetposted on 2003-07-03, 00:00 authored by Ramón Gómez Arrayás, Lanny S. Liebeskind
The first Mo-mediated [5+3] cycloadditions are reported. 3-Substituted pyranyl and pyridinyl molybdenum π-complexes participate in enantiocontrolled [5+3] cycloadditions and provide a new and efficient synthetic approach to oxa- and aza[3.3.1]bicyclics of high enantiomeric purity. The reaction proceeds in good to excellent yields and with complete regio- and endo-selectivities; it diverts to a [2+3] cycloaddition pathway when 2-substituted heterocycle π-complexes are used. This methodology, coupled with a variety of general demetalation protocols, holds much promise in synthetic applications.