The development of a Selectfluor®-mediated oxidative Mannich reaction

Tertiary Amine Coupling by Oxidation for Selective Labeling of Dimethyl Lysine Post-Translational Modifications

Lysine dimethylation (Kme2) is a crucial post-translational modification (PTM) that regulates biological processes and is implicated in diseases. There is significant interest in globally identifying these methylation marks. Unfortunately, this remains challenging due to the lack of robust technologies for selectively labeling Kme2. To address this, we present a chemical method named tertiary amine coupling by oxidation (TACO). This method selectively modifies Kme2 to aldehydes using Selectfluor and a base. The resulting aldehydes from Kme2 were then functionalized using reductive amination, thiolamine, and oxime chemistry. We successfully demonstrated the versatility of TACO in selectively labeling Kme2 peptides and proteins in complex cell lysate mixtures with varying payloads, including affinity tags and fluorophores. We further showed the application of TACO chemistry for the identification of Kme2 sites at a single-molecule level by fluorosequencing. We discovered novel 30 Kme2 sites, in addition to previously known 5 Kme2 sites, by proteomics analysis of TACO-modified nuclear extracts. Our work establishes a unique strategy for covalently modifying Kme2, facilitating the global identification of low-abundance Kme2-PTMs and their sites within complex cell lysate mixtures.

Selectfluor-mediated oxidative methylenation of amide with N,N-dimethylpropanamide for N,N′-methylenebisamide synthesis

A simple and efficient approach for the synthesis of N,N′-methylenebisamides through a Selectfluor-mediated oxidative reaction of aromatic amides and N,N-dimethylpropanamide (DMP) is described. Remarkable results clearly reveal that DMP plays a dual role in this reaction, as both a one-carbon source and an environment-friendly solvent. Moreover, the process provides new strategies for the synthesis of bisamides with advantages of operationally simple, insensitive to atmospheric conditions, and good to high yields.

Visible-light-mediated oxidative demethylation of N6-methyl adenines

A novel solution for the chemical modulation of RNA epigenetics via biologically compatible photo-catalysis under visible light irradiation has been described.

Metal-free intermolecular C–O cross-coupling reactions: synthesis of N-hydroxyimide esters

Selectfluor-mediated intermolecular C–O cross coupling reaction for the synthesis of N-hydroxyimide esters was achieved under metal-free conditions.