An efficient and stereoselective procedure for the preparation of E-1-alkenylphosphonates by copper-mediated cross-coupling between 1,1-dibromo-1-alkenes and dialkyl phosphites is reported. The reaction allows for formal substitution of both bromine atoms, respectively, by an hydrogen and a dialkoxyphosphoryl.
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.
Catalytic Enantioselective Synthesis of Difluorinated Alkyl Bromides
作者:Mark D. Levin、John M. Ovian、Jacquelyne A. Read、Matthew S. Sigman、Eric N. Jacobsen
DOI:10.1021/jacs.0c07043
日期:2020.9.2
facilitated the development of an improved catalyst providing higher enantioselectivity with lower catalyst loadings. The versatility of the difluoroalkyl bromide products was demonstrated via highly enantiospecific substitution reactions with suitably reactive nucleophiles. The origins of enantioselectivity were investigated using computed interaction energies of simpli-fied catalyst and substrate structures
Enantioselective Total Synthesis of (+)‐Eucophylline
作者:Iman Traboulsi、Nitin S. Dange、Vincent Pirenne、Frédéric Robert、Yannick Landais
DOI:10.1002/chem.202200088
日期:2022.3.16
Two strategies based respectively on the free-radical carbo- and sulfonyl-cyanation of cyclopropenes and cyclobutenes were developed to achieve the totalenantioselectivesynthesis of (+)-eucophylline, a monoterpene alkaloid isolated from Leuconotis eugenifolius.