%0 Journal Article
%T Pd-Catalyzed Umpolung of ¦Ð¨CAllylpalladium Intermediates: Assembly of All-Carbon ¦Á-Vinyl Quaternary Aldehydes through C(sp3)¨CC(sp3) Coupling
%J -
%D 2018
%R https://doi.org/10.1021/acscatal.8b03814
%X Construction of sterically congested all-carbon quaternary centers represents a formidable challenge in synthetic chemistry. The method described herein provides direct and facile access to a series of structurally diverse and synthetically useful aliphatic aldehydes, bearing an all-carbon ¦Á-vinyl quaternary center and a 1,5-diene functionality, through Pd-catalyzed umpolung of vinylethylene carbonates (VECs). The reaction features electrophilic-to-nucleophilic reactivity reversal of the VEC-derived ¦Ð-allyl-palladium intermediate via an unusual ¦Â-hydride elimination process, and the resultant enolate is chemoselectively coupled with allylic acetate to form an ¦Á-vinyl aldehyde embedded with an all-carbon quaternary center
%U https://pubs.acs.org/doi/10.1021/acscatal.8b03814