The continuous flow approach offers many attractions for Organometallic Chemistry
- ease of maintaining inert conditions
- control of reaction exotherms
- immediate inline use of unstable reactive intermediate species
- efficient uniform mixing
- reduced handling of potentially pyrophoric reagents
- elimination of temperature gradients and reactor hot spots
Unfortunately, pumping moisture sensitive reagents using syringe pumps or piston pumps provides its own set of challenges. Syringe pumps suffer from wetted surfaces that are repeatedly exposed to air and piston pumps can suffer from accumulation of particles in the valves.
However the revolutionary V-3 pump (as used in the Vapourtec E-Series) pumps organometallic reagents such as BuLi, DIBAL-H and Grignard reagents as easily at water!
The V-3 Pump
Anyone who has tried to pump organometallic reagents knows that they can present certain challenges, due to their sensitivity to air and moisture.
But these challenges are eliminated with the revolutionary new Vapourtec V-3 pump.
- Based on the peristaltic principle, it can self prime even with pipes initially full of air. The presence of a gas bubbles causes no problems at all.
- Reagents can be fed directly from a bottle with a septum. There is never any need to pressurise reagent bottles.
- The wetted area inside the V-3 pump is small. Drying the pump with anhydrous solvent is simple and rapid.
- The occasional generation of suspended particles of insoluble salts due to small amounts of moisture presents the pumps no problem, as there are no check valves or sliding seals.
- Where a quench is required for a cooled reaction, the E-Series system offers an affordable 3rd pump option.
Simple Inert Gas Blanketing of Reagents
Like all new R-Series systems, the E-Series includes a built in low pressure regulator and distribution manifold. A single inert gas supply of up to 8 bar pressure is regulated internally supplying the inert gas precisely controlled to 40 mbar at 4 outlets. The gas is delivered via the supplied tubing and needles directly through the bottle septum allowing reagents to be kept under an inert atmosphere and drawn directly from the reagent bottle.
No more surprisingly porous balloons or complex home made gas distribution systems.
See reference publication:
Continuous Flow-Processing of Organometallic Reagents Using an Advanced Peristaltic Pumping System and the Telescoped Flow Synthesis of (E/Z)-Tamoxifen (P. R. D. Murray, D. L. Browne, J. C. Pastre, C. Butters, D. Guthrie, S. V. Ley, Org. Process Res. Dev. 2013 17 (9), 1192-1208) DOI: 10.1021/op4001548
