Pd(ii)-catalyzed B(9)-alkynylation of o/m-carboranes

Abstract

Alkyne motifs are important building blocks in organic syntheses. Therefore, introducing alkynyl groups into molecules is highly desirable. Herein, we developed a Pd(II)-catalyzed selective B(9)-alkynylation of o-carboranes and m-carboranes with ⁱPr₃SiCCBr as the alkynylated reagent. Ratios of 6 : 1 for o-carboranes and >20 : 1 for m-carboranes were detected in this reaction. Desilylation of the resultant product affords carboranyl acetylene, which can undergo further transformation to provide a diverse range of functional carboranes.