Mono- and Bis-Acrolein Derivatives by Reliable and Efficient One-Step Methylenation of Aldehyde Precursors
作者:Leo Paquette、Kallol Basu、Jonathan Richards
DOI:10.1055/s-2004-834866
日期:——
A series of aldehydes carrying different functional groups was transformed directly into the α-methylene derivatives. Dialdehydes behaved comparably at both active sites. When keto aldehydes are involved, excellent levels of chemoselectivity are observed, with the ketone substructures exhibiting no sign of reactivity.
Synthesis of Planar-Chiral Paracyclophanes via Samarium(II)-Catalyzed Intramolecular Pinacol Coupling
作者:Tsuyoshi Ueda、Nobuhiro Kanomata、Hajime Machida
DOI:10.1021/ol0506258
日期:2005.6.1
[reaction: see text] A series of [n]paracyclophanediols (n = 8-12) was synthesized by samarium-catalyzed pinacolcoupling for their ansa-bridge formation. Enantiomerically pure [n]paracyclophane esters were derived from the diols in a several steps via chiral resolution (for n = 10) or via crystallization-induced asymmetric transformation (for n = 11) by using amino alcohol auxiliaries and their selective