Ruthenium-Catalyzed Allylic Alkylations of Chelated Enolates Using Vinyl Dioxolanon-2-ones
作者:Anton Bayer、Uli Kazmaier
DOI:10.1021/jo501877q
日期:2014.9.5
4-Vinyl-substituted 1,3-dioxolan-2-ones are found to be good substrates for Ru-catalyzed allylic alkylations of chelated amino acid ester enolates. cis-1,3-Dioxolan-2-ones are more reactive than the corresponding trans-isomers. The attack occurs preferentially with regioretention at the position of the leaving group with perfect chirality transfer. Therefore, this protocol is a good complement to the Pd-catalyzed processes, which give only linear products with this type of substrate.
Mizojiri, Ryo; Kobayashi, Yuichi, Journal of the Chemical Society. Perkin transactions I, 1995, # 17, p. 2073 - 2076
作者:Mizojiri, Ryo、Kobayashi, Yuichi
DOI:——
日期:——
An Efficient, Stereoselective Approach to <i>s</i><i>yn</i>-1,2-Diols Protected as Cyclic Carbonates
Enantioenriched 4-hydroxyalk-2-ynyl carbonates (or benzoates) have been prepared by stereoselective zinc-mediated addition of alkyl 2-propynyl carbonates (or their benzoate analogues) to aldehydes. Their partial reduction to Z-olefins followed by cyclization under mild Pd-catalyzed conditions allowed a straightforward access to enantioenriched syn-1,2-diols protected as cyclic carbonates.