Ir/Ni Hat Screening Kit
Native functionality in triple catalytic cross-coupling: sp3 C–H bonds as latent nucleophiles
Megan H. Shaw, Valerie W. Shurtleff, Jack A. Terrett, JamesD. Cuthbertson, David W. C. MacMillan
Science 10 june 2016 : 1304-1308
3 sets of reaction conditions with iridium catalysts Ir(dF-CF3-ppy)2(dtbbpy)PF6 and Ir(ppy)(dtbbpy)2PF6, NiBr2*3H2O, two ligands 4,7-dOMe-phen and 4,4’-dOMe-bpy and two bases Quinuclidine and 3-Acetoxy-quinuclidine. 15 reaction vials total.
This kit requires EvoluChem™ PhotoRedOx Box – HCK 1006-01-016 and EvoluChem™ Light Source 18W-450 nm – HCK 1012-01-002 as well as Syringe, decapper and reaction block included in the EvoluChem Starter Kit HCK1006-01-001
The typical protocol is performed at 0.25 mol/l using a solution containing two coupling components. Each sealed reaction vial contains
0.25 µmol of photocatalyst, 0.5 µmol Ni catalyst, 0.5 µmol ligand and 27.5 of µmol base. The Ir/Ni photoredox kit contains 3 sets of 5 vials allowing the screening of three different substrate combinations or solvents. Sparging reaction solvents with nitrogen or argon while transferring reagents is important to achieve highest conversions of product.
Protocol at 100 µl volume reaction condition
- Prepare the required volume of substrate solution at 0.25 mol/L containing both coupling substrates. For example, 600 µl solution for 5 reaction conditions (100 µl extra to compensate for evaporation). Reported reaction condition uses DMSO as solvent with addition of 40 equiv. of H2O.
- Degas substrate solution with subsurface sparging via N2 or Ar line with exit needle for 5 minutes.
- Using a clean and dry syringe, add 100 µl of the substrate solution to each reaction vial.
- Stir the reaction vials for 5 minutes prior to turning on the light to allow catalysts to fully dissolve.
- Turn on lamp and stir vials for 16 to 24 hours (or longer if necessary). Be sure to plug in fan to maintain RT.
- Upon completion of reaction, remove the vial caps using a decapper.
- Prepare analytical sample for each reaction condition with 5 µl sample diluted into 200 µl in either DMSO or water/acetonitrile 50/50. Alternatively, reaction solvent can be evaporated in vacuo and crude mixture diluted in water/acetonitrile prior to preparation of analytical sample.
- Analyze resulting analytical samples by LC/MS.