Photomethylation Kit

Photomethylation Kit:

2 sets of photomethylation reaction conditions with 2 iridium catalysts, AcOOtBu and 4 different solvent systems 16 reaction vials total
This kit requires EvoluChem reaction block (HCK1006-01-002) included in the EvoluChem Starter Kit (HCK1006-01-001)

The typical protocol is performed at 0.05 mol/l concentration reaction condition using a solution of substrate in 4 different solvents. Each sealed reaction vial contains 0.1 µmol of photocatalyst and 12.5 umol of tert-butyl peracetate. Based on the concentration of the substrate stock solution and the volume added, the following reaction stoichiometry can be achieved with the standard photomethylation kit.  See table below. Should solubility of substrate be an issue, lower concentrations can be used although longer reaction times may be required. The photomethylation kit contains four solvent mixtures.  If the user prefers, alternate solvents can be screened. It is recommended that alternative solutions be prepared at 0.05 M or 0.1M with 10 equiv. of trifluoroacetic acid based on substrate. Sparging reaction solvents with nitrogen or argon while transferring reagents is important to achieve highest conversions of product.  See protocol diagram for instructions.

Protocol at 50 µl volume reaction condition

  • Prepare the required volume of substrate solution at 0.05 mol/L in each solvent using the empty stock solution vials for each solvent. For example, 150 µl solution for 2 reaction conditions (50 µl extra to compensate potential evaporation).
  • Degas first substrate solution with subsurface sparging via N2 or Ar line with exit needle for 5 minutes.
  • Using a clean and dry syringe, add 50 µl of the substrate solution to each reaction vial.
  • Repeat steps 2 and 3 for each substrate solvent mixture.
  • Stir the reaction vials in the photochemical device for 18 to 24 hours.
  • 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.