6462-19-7Relevant articles and documents
Iterative synthesis of alkenes by insertion of lithiated epoxides into boronic esters
Bojaryn, Kevin,Fritsch, Stefan,Hirschhaüser, Christoph
supporting information, p. 2218 - 2222 (2019/04/10)
The insertion of lithiated epoxides into boronic esters followed by thermal syn-elimination provides a stereospecific entry to alkenes. This process avoids transition metals and is amenable to iteration to provide higher substitution patterns.
Highly Stereoselective Synthesis of Tetrasubstituted Acyclic All-Carbon Olefins via Enol Tosylation and Suzuki-Miyaura Coupling
Li, Beryl X.,Le, Diane N.,Mack, Kyle A.,McClory, Andrew,Lim, Ngiap-Kie,Cravillion, Theresa,Savage, Scott,Han, Chong,Collum, David B.,Zhang, Haiming,Gosselin, Francis
supporting information, p. 10777 - 10783 (2017/08/15)
A highly stereocontrolled synthesis of tetrasubstituted acyclic all-carbon olefins has been developed via a stereoselective enolization and tosylate formation, followed by a palladium-catalyzed Suzuki-Miyaura cross-coupling of the tosylates and pinacol boronic esters in the presence of a Pd(OAc)2/RuPhos catalytic system. Both the enol tosylation and Suzuki-Miyaura coupling reactions tolerate an array of electronically and sterically diverse substituents and generate high yield and stereoselectivity of the olefin products. Judicious choice of substrate and coupling partner provides access to either the E- or Z-olefin with excellent yield and stereochemical fidelity. Olefin isomerization was observed during the Suzuki-Miyaura coupling. However, under the optimized cross-coupling reaction conditions, the isomerization was suppressed to 5% in most cases. Mechanistic probes indicate that the olefin isomerization occurs via an intermediate, possibly a zwitterionic palladium carbenoid species.
Efficient synthesis of polysubstituted olefins using stable palladium nanocatalyst: Applications in synthesis of tamoxifen and isocombretastatin A4
Ganapathy, Dhandapani,Sekar, Govindasamy
, p. 3856 - 3859 (2014/08/18)
A phosphine-free stable palladium nanocatalyst was used for an efficient synthesis of polysubstituted olefins from N-tosylhydrazones and aryl iodides. This methodology was successfully utilized in the synthesis of biologically important tamoxifen and isocombretastatin A4. The nanocatalyst was easily recovered and reused without any apparent loss in size and catalytic activity.
