Herein, a palladium-catalyzed semi-hydrogenation of alkynes to E- and Z-alkenes employing EtOH as hydrogenating agents was reported. The selectivity of the reaction system was effectively controlled by ligand/additive and solvent regulation. The use of sodium acetate/triethanolamine (NaOAc/TEOA), THF and (1R,2R)-bis[(2-methoxypheny)phenyl- phosphino]ethane ((R,R)-DIPAMP), CH3CN was critical for the stereoselective semihydrogenation of alkynes. The general applicability of this procedure was highlighted by the synthesis of more than 36 alkenes, with good yields and high stereoselectivities.
An efficient stereoselective synthesis of brevipolide M was established in 13 linear steps and 17.8% overall yields base on chiron approach. The key steps of our synthesis involved tandem homologation / tetrahydrofuran cyclization and sequential ring-closing metathesis (RCM) / double-bond migration in one-pot processes.
1,1-Disubstituted alkenes feature high steric hindrance, which renders their Wacker-type oxidation difficult. We demonstrated the stereoselective synthesis of 2-hydroxytetrahydrofurans via the Wacker-type oxidation of 3-methyl-3-buten-1-ols by using a PdCl2(MeCN)2/NO/BQ catalyst...
This new investigation describes an efficient three-component approach for the stereoselective synthesis of pyrrolo[2,1-a]isoquinolines from readily available isatins, chalcones and 1,2,3,4-tetrahydroisoquinoline without using any metal catalyst or additive.
Correction to “Regio- and Stereoselective Synthesis of C-4′ Spirocyclobutyl Ribofuranose Scaffolds and Their Use as Biologically Active Nucleoside Analogues”
