Fmoc-R-3-Aminoisobutyric acid

Fmoc-R-3-Aminoisobutyric acid is an R-configured, Fmoc-protected amino acid derivative built on the 3-aminoisobutyric acid scaffold, featuring a stereogenic center at the α-carbon and a side chain that presents a sterically constrained, branched aliphatic amine. The molecule contains the Fmoc carbamate on the α-amino group, a carboxylic acid handle, and a free primary amine in the side chain that can participate in nucleophilic acylation, sulfonylation, or reductive transformations after appropriate chemoselective protection. The combination of a stable Fmoc protecting group and a reactive side-chain amino functionality enables controlled peptide coupling chemistry while preserving orthogonal derivatization options. As a chiral amino acid intermediate, it can be incorporated into peptide building blocks or converted into downstream functionalized analogs through protection/deprotection and selective functional group interconversions.

1. Peptide Synthesis

Fmoc-R-3-Aminoisobutyric acid supports solid-phase peptide synthesis workflows where the Fmoc carbamate enables base-mediated removal to generate an N-terminal amine for coupling. The α-carboxylic acid and stereodefined α-carbon provide compatibility with standard peptide coupling strategies, while the branched side-chain primary amine allows post-coupling modification to introduce additional functionality. Orthogonal protection of the side-chain amine during chain assembly can be used to maintain chemoselectivity, followed by deprotection for targeted derivatization. Incorporation of this chiral, sterically constrained residue can generate peptide sequences with altered backbone sterics and side-chain reactivity for structure-defined peptide analog construction.

2. Side-Chain Functionalization

Fmoc-R-3-Aminoisobutyric acid is well suited for amino acid derivatization programs that exploit the free primary amine on the side chain for controlled functional group installation. The branched 3-aminoisobutyric side chain can undergo acylation to form amides, sulfonylation to yield sulfonamides, or formation of urea and carbamate linkages, enabling access to a range of polarity and hydrogen-bonding patterns. Chemoselective protection of the side-chain amine during Fmoc deprotection and peptide coupling can preserve reaction control, while subsequent deprotection allows selective conjugation or further synthetic elaboration. Downstream products can serve as intermediates for peptidomimetics, affinity reagents, or chemically diversified libraries used in amino acid modification and molecular design studies.

3. Chemical Biology Labeling

Fmoc-R-3-Aminoisobutyric acid can be applied in chemical biology research where side-chain amine chemistry supports conjugation to probes, linkers, or capture handles after peptide or scaffold incorporation. The Fmoc-protected α-amino group provides a controlled entry point for assembling labeled peptides, while the stereodefined amino acid center can help maintain consistent conformational and recognition properties across analog series. Side-chain amine functionalization enables attachment of fluorescent tags, biotin-like affinity motifs, or reactive groups for subsequent click-type or nucleophile-driven coupling strategies. Resulting amino acid-containing constructs can function as biochemical research intermediates for studying molecular interactions, mapping binding determinants, and generating defined conjugates for analytical and mechanistic assays.

4. Peptidomimetics And SAR Studies

Fmoc-R-3-Aminoisobutyric acid can be utilized in peptidomimetic construction and SAR studies that require incorporation of a chiral, sterically restricted residue to modulate conformational preferences. The residue's branched aliphatic side chain and side-chain primary amine provide a tunable platform for generating analogs with altered steric bulk, solvation, and hydrogen-bonding capacity. Fmoc compatibility supports systematic synthesis of residue-substituted series, while side-chain derivatization enables rapid generation of amide, sulfonamide, and protected-amine variants for SAR-driven optimization. Chiral amino acid intermediate behavior supports stereochemically consistent library preparation for structure-activity relationship investigations and molecular scaffold refinement.

5. Process Chemistry Intermediate

Fmoc-R-3-Aminoisobutyric acid is suitable for process chemistry intermediate preparation where stable Fmoc protection on the α-amino group supports controlled downstream transformations. The presence of a carboxylic acid and a primary side-chain amine allows route design that can include selective protection, activation, and chemoselective functional group interconversions to reach targeted protected or activated amino acid derivatives. Stereochemical integrity at the R-configured center supports manufacturing of chiral building blocks for peptide-based fine chemicals and process-scale synthesis of amino acid derivatives. The compound's functional group set can be leveraged to produce downstream intermediates for pharmaceutical intermediate preparation, specialized peptide building block manufacturing, and industrial fine chemical synthesis where orthogonal protection strategies are integral to reliable scale-up.

1. The effect of sex on immune responses to a homocitrullinated peptide in the DR4-transgenic mouse model of Rheumatoid Arthritis

2. Myotropic activity and immunolocalization of selected neuropeptides of the burying beetle Nicrophorus vespilloides (Coleoptera: Silphidae)

3. Multifunctional peptide-oligonucleotide conjugate promoted sensitive electrochemical biosensing of cardiac troponin I

4. Spatiotemporal delivery of nanoformulated liraglutide for cardiac regeneration after myocardial infarction

5. An Isolated TCR αβ Restricted by HLA-A* 02: 01/CT37 Peptide Redirecting CD8+ T Cells to Kill and Secrete IFN-γ in Response to Lung Adenocarcinoma Cell Lines