Lewis Acid Mediated Cyclizations: Diastereoselective Synthesis of Six- to Eight-Membered Substituted Cyclic Ethers
作者:Arun Ghosh、Anthony Tomaine、Kelsey Cantwell
DOI:10.1055/s-0036-1589054
日期:2017.9
Lewis acid catalyzed synthesis of medium-sized cyclicethers in a diastereoselective manner. Cyclicethers are widely abundant in natural products. Cyclicether templates are also utilized in drug design and medicinal chemistry. Although the synthetic processes for this class of compounds have been studied extensively with respect to five- and six-membered rings, medium-sized cyclicethers are synthetically
We developed a copper(II) triflate-bisphosphine complex catalyzed olefin migration and Prins cyclization which lead to the synthesis of substituted tetrahydropyran derivatives. The protocol is convenient and a variety of substituted tetrahydropyrans were obtained in good to excellent yields with excellent diastereoselectivities.
Stereoselective Synthesis of Substituted Oxocene Cores by Lewis Acid Promoted Cyclization
作者:Arun K. Ghosh、Anthony J. Tomaine、Kelsey E. Cantwell
DOI:10.1021/acs.orglett.5b03411
日期:2016.2.5
Substituted oxocene derivatives have been synthesized by Lewis acid catalyzed reactions of ε-hydroxyalkene and substituted aromatic aldehydes. The Cu(OTf)2-bis-phosphine catalyzed reaction typically provides substituted dihydropyran derivatives through an olefin migration followed by a Prins cyclization. The corresponding reaction catalyzed by TMSOTf or BF3·OEt2 provided eight-membered cyclic ethers
Palladium-catalyzed remote arylative substitution was achieved for the reaction of arylboronic acids with alkenes possessing a distant acetoxy group via nondissociative chain walking and β-acetoxy elimination.