Total Synthesis of Linoxepin through a Palladium-Catalyzed Domino Reaction
作者:Lutz F. Tietze、Svenia-C. Duefert、Jérôme Clerc、Matthias Bischoff、Christian Maaß、Dietmar Stalke
DOI:10.1002/anie.201209868
日期:2013.3.11
Convergent and elegant: Linoxepin (see picture), a new lignan with an unusual oxepin moiety, has been synthesized in only 10 steps. The protecting‐group‐free totalsynthesis includes a palladium‐ catalyzed Sonogashira reaction and a domino carbopalladation/Heck reaction of an allylsilane.
nickel-catalyzed reductive tandem cyclization of the elaborated β-bromo acetal with a dibenzoxepin scaffold was invented to strategically construct the remaining two rings in linoxepin. The generated diasterodivergent intermediates could be easily converted to both enantiomers of this unique cyclolignan molecule via facile oxidations, thus realizing enantiodivergent total synthesis of linoxepin for