N-α-Boc-N-ε-Fmoc-L-lysine is a doubly protected lysine derivative in which the α-amino group is protected as a Boc carbamate and the ε-amino side chain is protected as an Fmoc carbamate, retaining the lysine backbone with a free carboxylic acid functionality. The molecule contains both protected amines and an unprotected carboxyl group, with stereochemistry indicated as L at the α-carbon, and the Boc and Fmoc groups provide orthogonal protection that helps control chemoselectivity during stepwise assembly of peptide fragments. In peptide chemistry and solid-phase peptide synthesis workflows, this protected amino acid is used as a precursor for introducing a lysine residue bearing orthogonally removable amino protections, supporting the preparation of peptides and amino acid derivatives for structure-activity studies and analytical method development.
CAT No: CP01418
CAS No:84624-27-1
Synonyms/Alias:Boc-Lys(Fmoc)-OH;84624-27-1;N-Boc-N'-Fmoc-L-Lysine;ST51012428;N-Boc-N-Fmoc-L-Lysine;Nalpha-Boc-Nepsilon-Fmoc-L-lysine;N-epsilon-FMOC-alpha-t-BOC-L-LYSINE;PubChem14939;15435_ALDRICH;SCHEMBL999302;N|A-Boc-N|A-Fmoc-L-lysine;15435_FLUKA;CTK8C6853;JYEVQYFWINBXJU-QFIPXVFZSA-N;MolPort-003-926-792;N-a-Boc-N-Epsilon-Fmoc-L-lysine;ZINC5460008;CB-349;AKOS015922788;RTR-026160;N(alpha)-boc-N(epsilon)-fmoc-L-lysine;AJ-54145;AK-50166;K511;KB-59036
N-α-Boc-N-ε-Fmoc-L-lysine is a protected lysine derivative featuring the L-lysine stereocenter at the α-position and orthogonally protected amino functionalities: an N-α Boc carbamate and an N-ε Fmoc carbamate. The molecule retains a free carboxyl group (or carboxyl functionality depending on the supplier form) and a protected primary side-chain amine, enabling controlled transformations without cross-reacting during peptide coupling. The Boc and Fmoc groups provide orthogonal deprotection windows that support sequential peptide assembly, while the carbamate carbonyls and aromatic fluorenyl motif impart distinct polarity and analytical signatures. As a chiral, bifunctionally protected amino acid building block, N-α-Boc-N-ε-Fmoc-L-lysine participates in protected amino acid synthesis routes and can be converted downstream into lysine-containing peptide fragments, conjugation-ready intermediates, and stereochemically defined lysine analogs.
1. Peptide Synthesis
N-α-Boc-N-ε-Fmoc-L-lysine is used in peptide synthesis workflows where orthogonal N-protection is required for lysine incorporation into protected peptide chains. The α-Boc carbamate and ε-Fmoc carbamate protect the two amine sites with different deprotection chemistries, supporting stepwise formation of peptide bonds while preventing premature side-chain coupling. The lysine backbone provides the standard amino acid linkage chemistry at the α-position, and the protected side-chain amine can be carried through multiple coupling cycles until the desired stage of deprotection. The resulting lysine-containing peptide building blocks and peptide analogs are suitable for solid-phase or solution-phase assembly strategies that require controlled handling of basic side chains.
2. Protected Amino Acids
N-α-Boc-N-ε-Fmoc-L-lysine serves as a chiral protected amino acid intermediate for manufacturing and research-grade synthesis of selectively deprotected lysine derivatives. The orthogonal Boc/Fmoc protection pattern enables planned N-protection removal sequences, allowing conversion into mono-protected lysine species, lysine esters, or lysine-derived coupling partners without loss of stereochemical integrity. The carbamate-protected amines also reduce undesired side reactions such as self-condensation or uncontrolled amide formation during derivatization steps. Downstream, the compound can be employed to prepare lysine fragments for peptide building block preparation, combinatorial libraries, and process chemistry intermediate streams requiring predictable protecting-group behavior.
3. Side-Chain Functionalization
N-α-Boc-N-ε-Fmoc-L-lysine is applied in side-chain functionalization programs aimed at generating lysine derivatives for chemical biology and materials-related conjugation chemistry. The ε-amino functionality is masked as an Fmoc carbamate, enabling selective deprotection to reveal a reactive primary amine at a chosen synthetic stage, which can then be used for acylation, sulfonylation, or formation of targeted amide or urea linkages. The presence of the orthogonally protected α-amino group supports further peptide-compatible transformations while tuning the reactivity of the lysine side chain. The resulting functionalized lysine intermediates can be used to construct peptidomimetics, prepare conjugation-ready fragments, and support downstream scaffold diversification from a stereochemically defined amino acid core.
4. Bioconjugation Chemistry
N-α-Boc-N-ε-Fmoc-L-lysine is suitable for bioconjugation chemistry where lysine-based amide coupling and controlled deprotection are required to generate defined attachment points. The protected ε-amine reduces nonspecific reactivity during intermediate handling, while orthogonal deprotection can expose the lysine side-chain amine for subsequent conjugation to activated carboxylates, activated esters, or other electrophilic partners under controlled conditions. The carbamate protections help maintain structural integrity of the lysine unit during linker installation and purification steps, supporting the preparation of labeled peptides and conjugated biomolecule fragments. The compound thus functions as a stereodefined lysine precursor for constructing conjugates used in biochemical research workflows and analytical reference material generation.
5. Pharmaceutical Manufacturing
N-α-Boc-N-ε-Fmoc-L-lysine is used in pharmaceutical manufacturing and fine chemical production contexts that require robust, reproducible protected amino acid intermediates for peptide-based or peptide-derived products. The orthogonal Boc and Fmoc groups support controlled deprotection sequences that align with manufacturing-scale peptide assembly logic, reducing the risk of side reactions from multiple amine functionalities. The lysine scaffold provides a standardized handle for incorporating a basic side chain into peptide intermediates, which can later be converted into drug-substance-relevant fragments or process intermediates. The compound can be employed as a chiral building block in industrial peptide synthesis supply chains, including preparation of protected lysine units for consistent downstream coupling and purification workflows.
6. Analytical Research
N-α-Boc-N-ε-Fmoc-L-lysine is applied in analytical research as a structurally defined, chiral protected lysine reference material for method development and protecting-group behavior monitoring. The Fmoc chromophore and the Boc carbamate provide distinct spectroscopic and chromatographic features that can be leveraged to track deprotection progress, verify protecting-group integrity, and confirm identity of lysine-containing intermediates. The orthogonality of the two N-protecting groups enables staged analytical evaluation of selective removal, supporting characterization workflows for peptide building block preparation and intermediate qualification. The compound can also serve as a calibration or structural standard in studies focused on amino acid derivative stability, protecting-group selectivity, and analytical separation of closely related protected lysine species.
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