Regioselective and Stereoselective Entry to β,β-Disubstituted Vinyl Ethers via the Sequential Hydroboration/Suzuki–Miyaura Coupling of Ynol Ethers
作者:Weijian Cui、Mengyi Mao、Zuying He、Gangguo Zhu
DOI:10.1021/jo401523m
日期:2013.10.4
A highly regio- and stereoselectivesynthesis of stereodefined β,β-disubstituted alkenyl ethers featuring the sequential hydroboration/Suzuki–Miyaura coupling of ynol ethers has been described. A number of functional groups, including OMe, Ac, CO2Et, CN, halides, and alkyl, (hetero)aryl, and alkenyl groups, are well-tolerated under the reaction conditions. Furthermore, it allows a facile entry to the
Copper-Mediated Selective Cross-Coupling of 1,1-Dibromo-1-alkenes and Heteronucleophiles: Development of General Routes to Heterosubstituted Alkynes and Alkenes
site-selective, double, or alkynylative cross-coupling, therefore providing divergent and straightforward entries to numerous building blocks such as bromoenamides, ynamides, ketene N,N-acetals, bromoenol ethers, ynol ethers, keteneO,O-acetals, or vinylphosphonates and further expanding the copper catalysis toolbox with useful and versatile processes.
Copper-Catalyzed Coupling of 1,1-Dibromo-1-alkenes with Phenols: A General, Modular, and Efficient Synthesis of Ynol Ethers, Bromo Enol Ethers, and Ketene Acetals
An efficient and general copper-catalyzed method is reported for the synthesis of phenol-derived 1-bromoenol ethers, ynol ethers, and ketene acetals by chemodivergent copper-catalyzed cross-coupling between readily available 1,1-dibromo-1-alkenes and phenols.
Palladium-Catalyzed Hydroarylation, Hydroalkenylation, and Hydrobenzylation of Ynol Ethers with Organohalides: A Regio- and Stereoselective Entry to α,β- and β,β-Disubstituted Alkenyl Ethers
Pd-catalyzed reductive addition of organohalides, including aryl, alkenyl, and benzyl halides, to ynol ethers has been realized in the presence of 2-propanol, giving α,β- and β,β-disubstituted olefinic ethers in satisfactory yields with excellent regio- and stereoselectivity. It represents the first highlyregio- and stereoselective hydroarylation, hydroalkenylation, and hydrobenzylation of ynol ethers.
A Pd-catalyzed addition of boronic acids to ynol ethers has been realized, delivering trisubstituted vinyl ethers in good yields with perfect control of the regio- and stereoselectivity. The reaction proceeds under mild conditions and exhibits excellent functional group compatibility. Moreover, the resultant products can be converted into pentasubstituted benzenes via the tandem Diels–Alder/aromatization reaction.