Chemoselectivity and the Chan–Lam Coupling Reaction: Adding Amino Acids to Polymer-Coated Microelectrode Arrays

The placement of a peptide onto a microelectrode array is frequently complicated by the presence of multiple nucleophiles in the peptide. In the work reported here, we have found that the Chan–Lam coupling reactions used to site-selectively place thiol, alcohol, and amine nucleophiles onto diblock-copolymer-coated surfaces are chemoselective for the placement of thiol and alcohol nucleophiles on the arrays. This means that cysteine- and serine-containing peptides can be placed onto an array without any need to protect the N terminus of the peptide. Furthermore, it was found that placement of thiol groups onto an array with the Chan–Lam reaction using optimized reaction times leads to complete coverage of the electrodes. The extent of this coverage can be controlled by varying the reaction time in a manner that allows for the construction of arrays with a gradient of peptide concentrations.

 

Matthew D. Graaf and Kevin D. Moeller

J. Org. Chem., 2016, 81 (4), pp 1527–1534

DOI: 10.1021/acs.joc.5b02656

Publication Date: January 14, 2016