Microwave-assisted synthesis of neopentylethynlarylboronates for the construction of boronic acid-based fluorescent sensors for carbohydrates

ORGN 145

Shi-Long Zheng, wang@gsu.edu, Suazette Reid, Regan LeBlanc, and Binghe Wang, wang@gsu.edu. Department of Chemistry and Center for Biotechnology and Drug Discovery, Georgia State University, 33 Gilmer St., Atlanta, GA 30302-4089
Our lab has a long-standing interest in the design and synthesis of boronic acid-based fluorescent sensors for carbohydrates. Along this line, we have also developed a combinatorial approach to the synthesis of such sensors. For this we are in need of a large number of arylboronic acids with a terminal alkyne group, which can be used in the [2+3] Huisgen cycloaddition. Such ethynylaryl boronic acids (esters) were synthesized from commercially available bromoaryl boronic acids in three steps with good yields. The key reaction is microwave-facilitated selective formation of neopentyl trimethylsilylethynylaryl boronates by Sonogashira reaction from the corresponding bromides. The use of microwave was found to significantly improve the reaction yields and shorten the reaction time.