Removing residual metals from post reactions can be a major issue. The toxic nature of transition -metals has led to the reduction of tolerated residual concentration in active pharmaceutical ingre-dients (APIs) to single digit ppm. However, many important key steps, such as coupling reactions (Suzuki, Heck, Stille, Sonogashira, etc), ring closing metathesis (RCM), and hydrogenation, still require the use of metal catalysts.
Purification of the API from remaining metal by traditional methods (chromatography, activated -carbon, distillation, recrystallisation, ultrafiltration, or reverse osmosis) often leads to problems such as high costs, time consuming, low efficiency, and API losses. SiliCycle has developed an efficient alternative: SiliaBond® Metal Scavengers.
These scavengers are made with SiliCycle's high purity silica gel: SiliaFlash®, which does not suffer from polymers' shortcomings, (i.e.: limited choice of solvents, excessive -swelling, extensive washings, poor selectivity, and static charge).
SiliaBond Metal Scavengers have significantly improved the way APIs can be synthesized. Any metal containing catalyst can be used, even downstream, as there are efficient scavengers available for -metals such as Pd, Pt, Sn, Ru, Rh, Ni, Cr, etc. Treatment with Metal Scavengers will selectively reduce the metal concentration without affecting the API.
- Typical Experimental Conditions & Calculation
- Parameters Effect on Scavenging Efficiency
- SiliaBond Metal Scavengers Characteristics
- Scavenging Palladium Catalysts
- Scavenging Pd(dppf)Cl2 Catalysts
- Scavenging Rhodium Catalysts
- Scavenging Ruthenium Catalysts
- Scavenging a Nickel Catalyst
- Scavenging a Platinum Catalyst
- Scavenging a Tin Catalyst
- SiliaBond Metal Scavenger: Compatible with RCM Reaction
- SiliaBond (Bulk) & SiliaPrep (SPE) Scavenging Efficiency Comparison
- SiliaBond Metal Scavenger: Easily Scalable
- Metal Scavenging Using SiliaBond Thiol in Pictures
- Metal Scavenging Using SiliaPrep Thiol in Pictures
- Use of SiliaBond Cysteine
- Use of SiliaBond DMT
- Use of SiliaBond Imidazole
SiliaMetS® Cysteine (Si-Cys) is the silica bound equivalent of the amino acid Cysteine. By attaching the molecule to the backbone via the amino group, the thiol group remains free and accessible for higher metal scavenging efficiency. It is a versatile metal scavenger for a variety of metals including Pd, Sn, Ru, Pt, Cu, Rh, Cd and Sc under a wide range of conditions and the preferred metal scavenger for tin residues.
SiliaSep flash cysteine cartridges offer a superior alternative to the other cartridges available on the market .