Organic Chemistry Portal

Abstracts

Search:

Vinyl Thianthrenium Tetrafluoroborate: A Practical and Versatile Vinylating Reagent Made from Ethylene

Fabio Juliá, Jiyao Yan, Fritz Paulus and Tobias Ritter*

*Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany, Email: rittermpi-muelheim.mpg.de

F. Juliá, J. Yan, F. Paulus, T. Ritter, J. Am. Chem. Soc., 2021, 143, 12992-12998.

DOI: 10.1021/jacs.1c06632


see article for more reactions

Abstract

A bench-stable, crystalline vinyl thianthrenium salt can be readily prepared from ethylene gas at atmospheric pressure in one step and is broadly useful in annulation chemistry of (hetero)cycles, N-vinylation of heterocyclic compounds, and palladium-catalyzed cross-coupling reactions.

see article for more examples

Competition experiment between 1-d3 and vinyl bromide; analysis by NMR spectroscopy and mass spectrometry.



Suzuki-type vinylation of aryl organoboron compounds using vinyl-TT+

Under ambient atmosphere, a 20 mL vial equipped with a teflon-coated magnetic stirring bar was charged with organoboron species (0.300 mmol, 1.00 equiv.), Pd(dba)2 (8.6 mg, 15 µmol, 5.0 mol%), P(o-tol)3 (10.0 mg, 33.0 µmol, 11.0 mol%) and t-BuOLi (36.0 mg, 0.450 mmol, 1.50 equiv.). The vial was transferred into a N2-filled glove box. Subsequently, dry THF (6 mL, c = 0.05 M) was added into the vial. The reaction mixture was stirred for 2 min at 25 °C before vinyl thianthrenium salt (149 mg, 0.450 mmol, 1.50 equiv.) was added into the vial in one portion. The vial was capped and was then transferred out of the glove box. The vial was placed on a heating block preheated at 60 °C where the reaction mixture was stirred for 16 h. The reaction mixture was cooled to 25 °C and filtered through a pad of celite eluting with DCM (20 mL). The filtrate was collected and concentrated under vacuum to roughly 5 mL. Silica gel (approximately 300 mg) was added, and the mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica gel to give corresponding product. [Note: unless otherwise mentioned, t-BuOLi stored at ambient atmosphere was used. When extra-dry t-BuOLi stored in the glovebox was used, poor yields were obtained].


Key Words

vinylation, Suzuki coupling


ID: J48-Y2021