Fmoc-4-Methoxy-D-Phenylalanine is an Fmoc-protected, non-natural amino acid derivative featuring a D-configured α-amino acid backbone bearing a phenyl ring substituted with a 4-methoxy group. The molecule contains an N-terminus masked by the fluorenylmethoxycarbonyl (Fmoc) protecting group, along with a free carboxylic acid functionality and a side chain that provides an aryl ether (methoxy) substituent for altered polarity and aromatic interactions relative to unsubstituted phenylalanine. As a protected amino acid building block, it is used in peptide synthesis workflows such as stepwise assembly and labeling strategies where the Fmoc group supports controlled chemoselectivity at the amino functionality while the 4-methoxy phenyl side chain can be incorporated into peptide analogues for structure-activity and binding studies.
CAT No: CP15507
Fmoc-4-Methoxy-D-Phenylalanine is a D-configured aromatic amino acid derivative in which the α-amino group is protected with a fluorenylmethoxycarbonyl (Fmoc) group and the side chain bears a para-methoxy substituent on the phenyl ring. The molecule therefore combines a chiral α-center with an electron-rich anisole functionality, while retaining a carboxylate that is typically handled as the activated acid form during peptide coupling workflows. The Fmoc carbamate provides orthogonal base-labile protection, enabling controlled deprotection under standard peptide-synthesis conditions without perturbing the aryl ether. The aromatic side chain can participate in π-π and hydrophobic interactions, and the methoxy group can undergo further functional-group transformations, making the compound a practical chiral building block for downstream amino acid derivatization and peptide analog construction.
1. Peptide Synthesis
Fmoc-4-Methoxy-D-Phenylalanine serves as a protected amino acid building block for solid-phase and solution-phase peptide synthesis where stereodefined incorporation of D-phenylalanine analogs is required. The Fmoc-protected amine supports stepwise coupling after base-mediated Fmoc removal, while the carboxyl group is suitable for amide-bond formation using standard peptide coupling activation strategies. The para-methoxy substituent on the benzene ring introduces an additional handle for tuning aromatic electronics and side-chain polarity in peptide sequences. Incorporation of this D-configured residue can be used to modulate conformational preferences and proteolytic stability in peptide constructs, supporting peptide library generation and sequence optimization studies.
2. Peptidomimetics And SAR
Fmoc-4-Methoxy-D-Phenylalanine is applicable to peptidomimetic design and structure-activity relationship (SAR) workflows that require systematic variation of aromatic side-chain substitution patterns. The chiral D-configuration at the α-carbon provides stereochemical control that can be leveraged to probe backbone recognition and binding-site tolerance to D-amino acid content. The anisole (4-methoxyphenyl) motif enables rational exploration of how electron-donating substituents affect hydrophobic contacts, aromatic stacking, and local hydrogen-bonding networks through the methoxy oxygen. The protected amino acid format supports rapid assembly of analog panels, enabling downstream evaluation of structure-function relationships using peptide-based scaffolds and constrained analogs.
3. Side-Chain Functionalization
Fmoc-4-Methoxy-D-Phenylalanine can be employed as a chiral precursor for side-chain functionalization strategies targeting the para-methoxy aromatic group. The methoxy substituent can potentially be transformed into other oxygenated or substituted aromatic functionalities through demethylation or electrophilic substitution routes, depending on the protecting-group strategy used for the peptide or intermediate stage. The Fmoc group allows orthogonal handling so that side-chain derivatization can be planned either before incorporation into a peptide or after selective deprotection to expose the amino functionality for further chemistry. The resulting functionalized aromatic amino acid derivatives can feed into fragment elaboration, medicinal chemistry intermediate preparation, and fine chemical synthesis where stereochemical integrity of the D-center must be maintained.
4. Chemical Biology Labeling
Fmoc-4-Methoxy-D-Phenylalanine supports chemical biology and biomolecular labeling approaches that rely on incorporating defined aromatic residues into peptides or protein fragments. The Fmoc-protected amine enables controlled peptide coupling to generate labeled constructs with a stereochemically defined D-amino acid residue positioned at a chosen sequence location. The para-methoxy group can serve as a chemically stable motif during assembly and may be used as a precursor for later conjugation chemistry, including conversion to more reactive aromatic derivatives when required by the labeling scheme. The aromatic side chain can also function as a recognition element in affinity probes, supporting the generation of sequence-defined reagents for binding studies and mechanistic investigations in biochemical research.
5. Pharmaceutical Manufacturing Intermediates
Fmoc-4-Methoxy-D-Phenylalanine is suitable for process chemistry and pharmaceutical intermediate preparation where protected amino acid derivatives are manufactured as feedstocks for downstream peptide or peptidomimetic production. The Fmoc carbamate protection strategy provides a controllable protection/deprotection handle that aligns with manufacturing workflows for stepwise assembly of protected peptide intermediates. The presence of the chiral D-center and the para-methoxy aromatic functionality makes the compound a defined stereochemical input for producing sequence-specific intermediates used in fine chemical synthesis. The compound's protected amino acid form can be incorporated into larger synthetic sequences while maintaining compatibility with standard peptide-coupling technologies, supporting scalable production of chiral peptide building blocks and related intermediates.
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