Generation of Arynes via Ate Complexes of Arylboronic Esters with an <i>ortho</i>-Leaving Group
作者:Yuto Sumida、Tomoe Kato、Takamitsu Hosoya
DOI:10.1021/ol401140d
日期:2013.6.7
An efficient method of generating aryne has been achieved by treating ortho-(trifluoromethanesulfonyloxy)arylboronic acid pinacol ester with tert-or sec-butyllithium. Monitoring the reaction by B-11 NMR has indicated that a boron-ate complex formed in situ is the eventual precursor that converts into aryne near room temperature. The prior formation of the ate complex at a low temperature has enabled us to use various arynophiles, including those bearing base-sensitive groups. The ready availability of the aryne precursors and mutual orthogonality in aryne generation with widely used ortho-silylaryl triflate have enhanced the utility of the method.