Side reactions in peptide synthesis. 12. Hydrogenolysis of the 9-fluorenylmethyloxycarbonyl group

Efficient Synthesis of Differentially Protected (S,S)-2,7- Diaminooctanedioic Acid, the Dicarba Analogue of Cystine

“…In terms of the envisaged use of our triprotected target compounds in peptide syntheses, the combination of protecting groups in 11a and 11b is not fully satisfactory due to the fact that hydrogenolytic deblocking of the Cbz group is compatible with neither the Pac nor the Fmoc [23] groups. We have demonstrated the compatibility of the Fmoc and Pac groups [24] and thus, in principle, the three protecting groups in 11b are fully orthogonal if the Cbz group is removed acidolytically rather than hydrogenolytically.…”

Further studies on the use of 2,2,2‐trichloroethyl groups for phosphate protection in phosphoserine peptide synthesis

“…This is not surprising in view of the work by Martinez et al (15) describing the lack of stability of Fmoc group during Pd-catalyzed hydrogenolysis. This is not surprising in view of the work by Martinez et al (15) describing the lack of stability of Fmoc group during Pd-catalyzed hydrogenolysis.…”

Solution‐Phase Peptide Synthesis

“…To alleviate this problem, polymer-bonded amines [55][56][57][58] have been shown to efficiently remove the Fmoc group in solution. This protecting group is stable in acidic reagents, but unexpectedly cleaved by catalytic hydrogenolysis [60,61], particularly in combination with ammonium formate over a palladium/charcoal catalyst [15]. This protecting group is stable in acidic reagents, but unexpectedly cleaved by catalytic hydrogenolysis [60,61], particularly in combination with ammonium formate over a palladium/charcoal catalyst [15].…”

“…6.2.1.6 Other Representative Protecting Groups Effective N a -protection is also provided by the allyloxycarbonyl (Alloc) group 14 [61,62]. The Alloc group can be readily removed through palladium catalyzed transfer of the allyl entry to various nucleophilic species under neutral conditions as shown in Scheme 6.9.…”