Synthesis of new thiol-derivatized aminophosphines and their catalytic activities in C--C coupling reactions

Abstract

A series of new aminophosphines [Ph$_{2}$PHN-C$_{6}$H$_{4}$-R, where R = $o$-SH (\textbf{4a}), $m$-SH (\textbf{4b) or }$p$-SH (\textbf{4c})] were readily synthesized from cheap starting materials by the phosphorylation reaction of $o$, $m$, and $p$-aminothiophenols with Ph$_{2}$PCl in the presence of triethyl amine. The new compounds were characterized by NMR and IR spectroscopy and microanalysis. In addition, aminophosphine ligands--palladium systems were investigated as precatalysts in C--C coupling reactions. Compounds \textbf{4b} and \textbf{4c }were proved to be excellent catalysts for Suzuki and Heck cross-coupling reactions.