Kp sil

General: All commercially available reagents and anhydrous solvents were ACS grade or better and were used as received.
Analytical thin-layer chromatography was carried out using glassbacked plates coated with fluorescent silica gel 60 F254 from Whatman (Partisil LK6D). Spots were visualized under natural light and UV illumination at λ = 254 and 365 nm. Flash chromatography was conducted on a Biotage SP1 automated flash chromatography system equipped with a fixed wavelength UV detector (λ = 254 nm). Samples were preabsorbed onto ready-made silica gel samplets and then applied on to normal-phase flash chromatography cartridges (Biotage KP-SIL, size according to requirements) and elution with a 0–100% EtOAc/hexane (0.5% acetic acid) gradient. ¹H and ¹³C NMR spectra were recorded at 400 and 100 MHz, respectively, using a Bruker AV-400 with sample changer (BACS 60). A purity of ≥95% (unless otherwise indicated) for the final compounds in this study was confirmed by analytical HPLC on a Waters HPLC system with PDA detector (set at λ = 254 nm) equipped with a Supelco Supelcosil LC-18 reverse-phase column (15 cm Å ~ 3 mm, 5 µm). Compounds screened in the current study also were characterized with respect to their mp and HRMS.

Aryl bromide (1.0 equiv), allylpalladium(II) chloride dimer (0.05 equiv), tri-tert-butylphosphonium tetrafluoroborate (0.20 equiv), and alkyne (1.2 equiv) (if solid at room temperature) were weighed and added to a MW vial equipped with a stir bar. The vial was covered with a rubber septum and placed under nitrogen atmosphere. In a separate scintillation vial, DABCO was weighed and dissolved in dry 1,4-dioxane (5 mL/mmol of aryl bromide). This DABCO solution and alkyne (if liquid at room temperature) were added to the MW vial via syringe, and the resulting mixture was bubbled with nitrogen for 5 min followed by stirring for 16 h at room temperature under nitrogen atmosphere. After 16 h, the crude reaction mixture was filtered through a short pad of Celite and concentrated in vacuo. The remaining residue was purified by flash chromatography on silica using forced flow of ethyl acetate/hexanes system on Biotage KP-Sil prepacked cartridges and using the Biotage SP-1 automated chromatography system to afford the cross-coupled product.