Step-by-Step Guide for KitAlysis™ High-Throughput Photocatalysis Reaction Screening Kit

Figure 1. Note: While the above scheme depicts a generic decarboxylative coupling reaction, High-Throughput Photocatalysis Screening Kit can be used for any photocatalytic transformation

Materials Required - Set up:

• 1 mylar bag from the KitAlysis™ High-Throughput Photocatalysis Reaction Screening Kit and you will use the following components - 24 x 1 pre-weighed catalysts in glass vials loaded with stir bars and topped with cap mat - 1 empty substrate stock solution vials (4 mL)
• 1 NEW KitAlysis 24-Well Reaction Block Replacement Film
• 1 (2 mL) ampule each of 4 of the following: DCM, DCE, DMF, MeCN (in ampule boxes)
• 1 NEW stir bars
• Photo KitAlysis™ Starter Kit: LED Controller, Blue LED Array, Photo Kitalysis Reaction Block (sold separately)
• KitAlysis™ Benchtop Inertion Box (sold separately) or glove box/glove bag

Additional (not included) items needed:

• Pipette (0-100 µL) & tips
• 2 (1 mL) syringes with long needles
• Your substrates
• Nitrogen (or Argon): from hood line or tank
• 2 stir plates
• HPLC vials, 96-well HPLC auto sampler block, or TLC plates

Set Up Procedure:

• Place a NEW KitAlysis™ 24-Well Reaction Block Replacement Film on reaction block lid (make sure all holes, including the temperature probe hole, line up with the corresponding holes on the film).
• Check all screws to ensure they are not stripped. Replace any stripped screws with provided replacements.
• Place the KitAlysis™ Benchtop Inertion Box with tubing connected to inert gas onto a stir plate (see KitAlysis™ Benchtop Inertion Box set-up for details).
• Place Photo KitAlysis™ 24-Well Reaction Block with lid into KitAlysis™ Benchtop Inertion Box. Start nitrogen flow and purge 5 minutes. Leave nitrogen flowing for remainder of set up.
• Weigh substrates into substrate stock solution vials according to recipe (provided in the downloadable excel file) omitting solvent. Add stir bar to vial mixture. Label as “Vial 1”.
• Partially open the lid on the KitAlysis™ Benchtop Inertion Box. Place “Vial 1” in the center hole located on the left-hand side of the Inertion Box diffuser tray. This vial placement allows for the best flow of inert gas (remove lid from the solid mixture before placing into the recommended hole, keeping the lid in the Inertion Box for later use if needed).
• Transfer the capped, 24-vial, preloaded catalysts into the reaction block making sure to load it according to the matching diagram on the packaging and the Reaction Block. Leave the mat on.
• Open 2 ampules of the desired solvent quickly place into the holes located along the bottom of the Inertion Box, below the Reaction Block.
• Once all components are in the KitAlysis Benchtop Inertion Box, close the lid and purge for an additional 5 minutes. Leave nitrogen flowing for remainder of set up.
• Purge needle and syringe in a nitrogen diffuser hole 2x by pulling and then pushing plunger. Using purged needle and syringe, add required solvent amount to open substrate mixture vial.
• Stir mixture until in solution (1-2 min). For slurries, see “additional tips” below.
• While mixture is stirring, carefully remove the cap mat from the 24-vial, preloaded bases in the reaction block.
• Dose 100 µL of “Vial 1” to vials A1-D6. You may have a very small amount of excess solution remaining for each mixture. Save it as a reaction standard for HPLC/TLC later.
• Take the Photo KitAlysis™ 24-Well Reaction Block lid and line up the screws with the holes in the plate.
• Screw on lid according to directions and pattern shown in the “additional tips” section below. Before removing Photo KitAlysis™ 24-Well Reaction Block from the Inertion Box, ensure that the lid is evenly sealed onto the base. Do this visual check as you go along to avoid having to unscrew the lid and screw again.
• Once completely sealed, remove the Photo KitAlysis™ 24-Well Reaction Block from the Inertion Box. Place on LED array and place LED array/reaction block on stir plate. Turn on controller and adjust light intensity to desired level to begin reaction.
• Make the internal standard solution in a bottle with a replaceable lid following the recipe below for HPLC analysis. TLC is also possible.
• At reaction completion, follow the below Work-Up Procedure to quench reactions, make them more suitable for analysis, and add internal standard.

Internal Standard Recipe

• 25 mL CH₃CN
• 7.7 mg Biphenyl (KitAlysis Internal Standard provided in the kit) There is excess in the bottle so be sure to weigh it out.

Note: This recipe makes 25 mL which is enough stock solution for both screening sets in the KitAlysis™ Photocatalysis Reaction Screening Kit. The amount of internal standard is 10 mol% per reaction, so a big product peak to small internal standard indicates a good reaction. Integrate to compare reactions against one another (product/internal standard).

Work-up Procedure and Analysis

• Turn off LED array. Remove reaction block lid using small, non-torque KitAlysis™ screwdriver.
• Check each vial for solvent loss, and record.
• Aliquot 500 µL of prepared quench solution to each vial.
• Replace lid, tighten middle screw and stir on stir plate for 2-3 minutes. DO NOT INVERT BLOCK.
• After 2-3 minutes of stirring, let plate rest (without stirring) for 5 minutes to allow insoluble material to settle out of solution to the bottom of the vials.
• While plate is resting, add 700 µL of acetonitrile to each 24 individually labeled (A1, A2 etc,) HPLC vials or to each of 24 wells of a 96-well HPLC/UPLC auto sampler block (see “additional recommended materials” below for suggestions on the auto sampler block and cap mat.
• Remove lid on Photo KitAlysis™ 24-Well Reaction Block carefully.
• Using a clean pipette each time, remove a 25 µL aliquot from each vial into corresponding HPLC vials or HPLC block. Be careful to pull material from the top of the vials to avoid any precipitate.
• Run on HPLC auto sampler. You may need to adjust the amount of acetonitrile from the suggested 700 µL to accommodate your unique HPLC system.

Figure 2. Sealing the Plate-screwing down the cover

Sealing the Plate-screwing down the cover

Sealing the plate properly is critical to success. The key is light, even pressure to the lid of the block to keep the cover flat while sealing.

1. Line-up screws making sure that the base and lid temperature probe holes line-up in the KitAlysis™ 24-Well Reaction Block.
2. Initially flush: Using your thumb and forefinger, press the lid of the box until it becomes flush with the vials. Then, using the KitAlysis™ Torque Screwdriver, insert screws until flush, but not tight, with the top of the box, following the cross pattern provided below. Check to see that the lid is evenly sealed onto the base on all sides. Do this visual check to avoid having to unscrew the lid and screw again.
3. Tighten: Repeat the same pattern until the KitAlysis™ Torque Screwdriver “clicks” indicating complete tightness. Go around the block once more for a final check to ensure all screws are tight.

Slurry Additions

Due to narrow opening of pipette tips, slurry additions will result in blockages. To aid in uniform dosing, simply snip off the end of the tip at the first marker (~10 mm). To ensure an evenly dispersed aliquot, it is critical that the mixture is stirring well while you draw aliquots for dosing into the corresponding reaction vial.

Figure 3. Snip Pipette