Palladium catalyzed regioselective B-C(sp) coupling via direct cage B-H activation: synthesis of B(4)-alkynylated o-carboranes.

ABSTRACT: Pd-catalyzed carboxylic acid guided regioselective alkynylation of cage B(4)-H bonds in o-carboranes has been achieved for the first time using two different catalytic systems. In the presence of 5 mol% Pd(OAc)₂ and 3 equiv. of AgOAc, the reaction of 1-COOH-2-R¹-C₂B₁₀H₁₀ with R₃SiC[triple bond, length as m-dash]CBr in ClCH₂CH₂Cl gives 4-(R₃SiC[triple bond, length as m-dash]C)-2-R¹-o-C₂B₁₀H₁₀ in moderate to high yields. This reaction is compatible with alkynes possessing sterically bulky silyl groups such as ⁱPr₃Si or ^t BuMe₂Si. Meanwhile, another catalytic system of Pd(OAc)₂

SUBMITTER: Quan Y 

PROVIDER: S-EPMC6024241 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature