Catalytic Organocopper Chemistry from Organosiloxane Reagents
作者:Jessica R. Herron、Vincenzo Russo、Edward J. Valente、Zachary T. Ball
DOI:10.1002/chem.200901438
日期:2009.9.7
Organosilanes serve as precursors to organocopper intermediates in a copper‐catalyzed addition to vinylepoxides (see scheme). Ligand structure has a significant effect on the reactivity of the organocopper intermediate, and the catalysis proceeds without the need for a stoichiometric silane activator such as fluoride.
Asymmetric Synthesis of α-Substituted Aldehydes by Pd-Catalyzed Asymmetric Allylic Alkylation−Alkene Isomerization−Claisen Rearrangement
作者:Barry M. Trost、Ting Zhang
DOI:10.1021/ol0624878
日期:2006.12.1
Enantiospecific aliphatic Claisen rearrangement was realized with generally high chirality transfer. The requisite substrates were synthesized via Pd-catalyzed asymmetric allylic alkylation (AAA) from easily obtained starting materials. After protection, the resultant bisallyl ethers underwent olefin isomerization and in situ Claisen rearrangement (ICR) to generate alpha-chiral aldehydes. Remarkable chemoselectivity