Abstract:A new process has been developed for the iridium(I)-catalyzed vinylic C-H borylation of α,β-unsaturated esters with bis(pinacolato)diboron. These reactions proceeded in octane at temperatures in the range of 80-120 °C to afford the corresponding alkenylboronic compounds in high yields with excellent regio-and stereoselectivities. The presence of an aryl ester led to significant improvements in the yields of the acyclic alkenylboronates. Crossover experiments involving deuterated substrates as well as a mixture of stereoisomers confirmed that this reaction proceeds via a 1,4-addition/ β-hydride elimination mechanism. Notably, this reaction was also used to develop a one-pot borylation/SuzukiMiyaura cross-coupling procedure.