Benzyloxycarbonyl protective group

Tpte [2-[(4-tritylphenyl)thio]ethyl] Z = Cbz benzyloxycarbonyl protecting group... 

Alternatively the benzyloxycarbonyl protecting group may be removed by treat ment with hydrogen bromide m acetic acid... 

Hydrogen bromide may be used to remove either the benzyloxycarbonyl or tert-butoxycarbonyl protecting group. The benzyloxycarbonyl protecting group may also be removed by catalytic hydrogenolysis. 

The benzyloxycarbonyl protecting group for amines is introduced in high yield using benzyl imidazole-carboxylate with a catalytic amount (5%) of dimethylamino-pyridine.[1953... 

BW Erickson, RB Merrifield. Use of chlorinated benzyloxycarbonyl protecting groups to eliminate Ne-branching at lysine during solid-phase peptide synthesis. J Am Chem Soc 95, 3757, 1973. 

Knudsen, K.R. and Holden, J. and Ley, S.V. and Ladlow, M. (2007). Optimization of Conditions for 0-Benzyl and A-Benzyloxycarbonyl Protecting Group Removal using an Automated Flow Hydrogenator. Synth. Catal, 349, 535-538. 

The first solid-phase peptide synthesis reported by Merrifield had some disadvantages, which were corrected in later versions of this synthesis. The main improvements were the replacement of benzyloxycarbonyl protective groups by the TFA-labile Boc protection, and the use of TFA-resistant linkers cleavable by HF. 

Like the benzyloxycarbonyl protecting group, the Boc group may be removed by treatment with hydrogen bromide (it is stable to hydrogenolysis, however) ... 

To add a leucine residue to the N terminus of the ethyl ester of Z-Phe-Gly, the benzyloxycarbonyl protecting group must first be removed. This can be accomplished by hydrogenolysis. 

When it is time to remove the benzyloxycarbonyl protective group, the compound is reacted with hydrogen in the presence of a catalyst. The cleavage of the benzyl group by hydrogenolysis (see Section 23.3) is followed by spontaneous decarboxylation of the carbamic acid. An example is provided by the following equation ... 

The -nitrobenzyl ester of cephalosporin has been cleaved cathodically to yield cephalosporin [65]. The widely used benzyloxycarbonyl protecting group for amines is cathodically removed, giving free amine, CO2, and toluene [66] ... 

For the reversible immobilization of amines to such linkers, the most frequently used strategy is conversion of the hydroxymethyl linkers into activated carbonic esters (Figure 14.7) [8, 39, 40]. These react with primary and secondary amines or hydrazines to form immobilized carbamates or carbazates analogous to the classical benzyloxycarbonyl protecting group. Amines and hydrazides attached by this strategy to Wang resin can be cleaved with TFA [8, 40]. 

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