Coupling Reactions¶
Amide¶
Peptide bond formation on solid phase and in solution.
Solid Phase¶
- Uronium-Based Coupling -- HATU, HBTU, COMU, and related uronium/guanidinium reagents.
- Phosphonium Reagents -- PyBOP, PyAOP, and related phosphonium coupling agents.
- Carbodiimide -- DIC-mediated coupling, typically with HOAt or HOBt as additive.
- BTC -- Triphosgene-mediated coupling for sterically hindered substrates.
Solution Phase¶
- DCC -- Dicyclohexylcarbodiimide coupling.
- EDC -- Water-soluble carbodiimide for aqueous-compatible couplings.
- CDI -- Carbonyldiimidazole-mediated activation.
- Solution-Phase Amide Coupling with DSC -- Disuccinimidyl carbonate activation.
- Active Esters -- Pre-formed active esters (e.g., NHS esters, pentafluorophenyl esters).
Other Reagents to Consider¶
- Acid fluoride (TFFH, cyanuric fluoride)
- Acid chloride (BTC, trichloroacetonitrile, thionyl chloride)
- T3P
- EEDQ and IIDQ
- Triazines
- PyBrOP
Ester¶
Solid Phase¶
- Esterification -- DIC/DMAP-mediated ester bond formation on resin.
Peptoid¶
Solid Phase¶
- Bromoacetic Acid and DIC -- Two-step peptoid coupling: bromoacetylation followed by amine displacement.