Scope of Palladium-Catalyzed Alkylative Ring Opening
作者:Mark Lautens、Sheldon Hiebert
DOI:10.1021/ja037550s
日期:2004.2.1
We have explored the scope of the palladium-catalyzed nucleophilic ringopening methodology. New highly selective and highly active catalysts have been found for the ringopening of oxabenzonorbornadienes. Employing these catalysts, the addition of various alkyl nucleophiles to oxabenzonorbornadiene has been achieved. In addition, reaction of diethylzinc with [3.2.1] oxabicyclic alkenes has been accomplished
A multinuclear palladium catalyst can be used to realize the efficient catalytic asymmetric alkylative ring-opening reaction of oxabicyclic alkenes using dimethylzinc. The use of (R)-BINOL-PHOS bearing bisphosphine and diol moieties is essential for achieving excellent catalytic performance; the corresponding monophosphine and hydroxy-protected derivatives showed lower catalytic activities and/or enantioselectivities. The generation of Pd/Zn-multinuclear complexes is a key feature of the present catalysis.
Palladium-Catalyzed Enantioselective Alkylative Ring Opening