Rink Acid resin (100-200 mesh)

Rink acid resin is a super acid-labile support for the solid phase immobilization of carboxylic acids ^[1] by Fmoc SPPS. Cleavage can be effected with as little as 10% AcOH in DCM, providing highly acid-sensitive products in high yields and purities. However, care must be taken to prevent product loss during synthetic manipulations ^[2], owing to the extreme acid sensitivity of this support. Treatment with HCl in THF ^[3] or Ph₂PCl2 ^[4] has been shown to efficiently convert this resin to the corresponding benzhydryl chloride, to which can be coupled a wide range of functional groups: hydroxylamines ^[3], alcohols, amines, acids and thiols ^[4]. Rink acid resin has also been converted to a trifluoroacetate with TFA and used in a similar manner to immobilize amines, thiols, alcohols, and phenols ^[5]. In a more detailed study, the same authors found 1 M trifluoroacetic anhydride in 2,6-lutidine to give superior results with less degradation of the linker ^{[6, 7]}. Rink resin trifluoroacetate has also been used to prepare purines ^{[8, 9]}.Cleavage of amines and alcohols from this support has been carried out with either 5% TFA in DCM ^[4] or 20% TFA in DCM ^[5]; thiols were released with either 5% TFA in DCM ^[4] or 95% aq. TFA ^[5].

Associated Protocols and Technical Articles
Protocols for Loading of Peptide Synthesis Resins

Literature references

^[1] H. Rink (1987) Tetrahedron Lett., 28, 3787.
^[2] H. U. Immer, et al. in ′Peptides, Chemistry, Structure &Biology, Proc. 11th American Peptide Symposium′, J. E. Rivier & G. R. Marshall (Eds), ESCOM, Leiden, 1990, pp. 1054.
^[3] S. L. Mellor & W. C. Chan (1997) J. Chem. Soc., Chem. Commun., 2005.
^[4] R. S. Garigipati (1997) Tetrahedron Lett., 38, 6807.
^[5] W.K.-D. Brill in ′First Conference on Synthetic Organic Chemistry′, www.mdpi.org/ecsoc, 1997.
^[6] W.K.-D. Brill (1998) Syn. Lett., 906.
^[7] R. A. Tommesi, et al. (1998) Tetrahedron Lett., 39, 5477.
^[8] W.K.-D. Brill (2001) Syn. Lett., 1097.
^[9] W.K.-D. Brill & C. Riva-Toniolo (2001) Tetrahedron Lett., 42, 65`5.

Replaces: 01-64-0012

Color (visual): white to yellow to beige
Appearance of substance (visual): beads
Loading (determined from the substition of the Fmoc-NH2 loaded resin): 0.35 - 0.80 mmol/g
Swelling Volume (in DMF): lot specific result
The polymer matrix is copoly (styrene - 1% DVB) 100 -200 mesh

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