Boc-3,4-Difluoro-D-Phenylalanine

Boc-3,4-Difluoro-D-Phenylalanine is a protected, non-natural amino acid derivative featuring a D-phenylalanine backbone bearing two fluorine atoms at the 3 and 4 positions of the aromatic side chain. The molecule contains a Boc-protected amino group and a free carboxylic acid, with the fluorinated benzyl side chain providing increased electronegativity and altered hydrophobic/aromatic character relative to unsubstituted phenylalanine. As a stepwise peptide-synthesis intermediate, the Boc protection supports chemoselective coupling at the carboxylate while the difluorinated aromatic functionality can be used to probe structure-property relationships, incorporate fluorinated residues into peptide analogues, or support analytical method development for fluorinated amino acid-containing sequences.

Designed for biological research and industrial applications, not intended for individual clinical or medical purposes.

CAT No: CP13005

CAS No:205445-51-8

Synonyms/Alias:205445-51-8;BOC-d-3,4-Difluorophenylalanine;Boc-3,4-difluoro-D-phenylalanine;boc-d-3,4-difluorophe;Boc-D-Phe(3,4-F2)-OH;boc-d-phe(3,4-dif)-oh;N-(tert-Butoxycarbonyl)-3,4-difluoro-D-phenylalanine;(2r)-2-[(tert-butoxycarbonyl)amino]-3-(3,4-difluorophenyl)propanoicacid;N-Boc-3,4-difluoro-D-phenylalanine;3,4-difluoro-d-phenylalanine,bocprotected;3,4-difluoro-d-phenylalanine,n-bocprotected;n-alpha-t-butyloxycarbonyl-d-3,4-difluorophenylalanine;(r)-2-(tert-butoxycarbonylamino)-3-(3,4-difluorophenyl)propanoicacid;(r)-2-tert-butoxycarbonylamino-3-(3,4-difluoro-phenyl)-propionicacid;(R)-2-((tert-butoxycarbonyl)amino)-3-(3,4-difluorophenyl)propanoicacid;AmbotzBAA1365;PubChem6124;AC1MC51I;14993_ALDRICH;Boc-D-Phe(3,4-F)-OH;SCHEMBL2573377;14993_FLUKA;CTK8B1154;CYAOPVHXASZUDE-LLVKDONJSA-N;MolPort-001-773-554

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M.F/Formula
C14H17F2NO4
M.W/Mr.
301.29

Boc-3,4-Difluoro-D-Phenylalanine is a D-configured, non-proteinogenic phenylalanine analog bearing two fluorine atoms on the aromatic ring and an N-terminal Boc protecting group. The difluoro substitution provides a distinct electronic and steric profile relative to standard phenylalanine, making this building block useful for structure-activity relationship (SAR) and conformational/electronic tuning in peptide and peptidomimetic design. As a protected amino acid, it is commonly handled as a synthetic intermediate for downstream peptide coupling workflows.

1. Peptidomimetic SAR Building

Boc-3,4-Difluoro-D-Phenylalanine is used by medicinal chemistry groups to introduce a fluorinated, D-amino-acid residue into peptide-like scaffolds for SAR studies. The 3,4-difluoro substitution on the phenyl ring is leveraged to modulate aryl electronics and local interaction patterns while the D-configuration supports non-natural backbone stereochemistry in peptide mimetics. This reagent is particularly relevant when researchers are optimizing sequence-dependent properties such as physicochemical balance and conformational preferences during lead refinement.

2. Peptide Synthesis With Boc

Boc-3,4-Difluoro-D-Phenylalanine serves as an N-Boc-protected amino acid building block for custom peptide assembly workflows, including solution-phase peptide synthesis and protected-residue fragment coupling strategies. The Boc group provides compatibility with standard peptide-manufacturing practices where N-protection is required prior to amide bond formation, and the difluorinated aromatic side chain allows incorporation of a non-natural residue without relying on post-synthetic aromatic functionalization. Teams developing modified peptides for chemical biology, assay reagents, or lead optimization commonly select this building block when they need a defined, fluorinated residue installed at a specific position.

3. Protease-Resistant Scaffold Design

Boc-3,4-Difluoro-D-Phenylalanine is frequently incorporated into non-natural peptide and peptidomimetic designs aimed at improving chemical robustness through stereochemical control and side-chain electronics. In practice, research teams use D-amino-acid residues to alter backbone recognition patterns, while the 3,4-difluoro phenyl ring provides an additional handle for tuning hydrophobicity and aromatic interaction behavior. This makes the building block a common choice in preclinical research chemistry programs that prepare defined analog panels for stability and structure-property investigations.

4. Fluorinated Analogue Reference Standards

Boc-3,4-Difluoro-D-Phenylalanine is also used in analytical and method-development contexts where defined fluorinated amino-acid residues are required as reference materials for characterization of peptide analogs and related intermediates. Analytical chemistry teams can use it to prepare well-defined standards or calibration/qualification compounds that reflect the exact residue identity used in synthesis. The presence of two fluorine atoms supports unambiguous structural confirmation and mass-based characterization in workflows that monitor fluorinated peptide components during purification and analytical verification.

Abbr
Boc-D-Phe(3,4-F2)-OH
InChI
1S/C14H17F2NO4/c1-14(2,3)21-13(20)17-11(12(18)19)7-8-4-5-9(15)10(16)6-8/h4-6,11H,7H2,1-3H3,(H,17,20)(H,18,19)/t11-/m1/s1
InChI Key
CYAOPVHXASZUDE-LLVKDONJSA-N
Canonical SMILES
CC(C)(C)OC(=O)NC(CC1=CC(=C(C=C1)F)F)C(=O)O

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