title: High yielding preparation of dicarba-closo-dodecaboranes using a silver(I) mediated dehydrogenative alkyne-insertion reaction.
abstract: The synthesis of 1,2-dicarba-closo-dodecaboranes (ortho-carboranes) is often low yielding which is a critical issue given the increasing use of boron clusters in material science and medicinal chemistry. To address this barrier, a series of Cu, Ag, and Au salts were screened to identify compounds that would enhance the yields of ortho-caboranes produced when treating alkynes with B10H12(CH3CN)2. Using a variety of functionalized ligands including mono- and polyfunctional internal and terminal alkynes, significant increases in yield were observed when AgNO3 was used in catalytic amounts. AgNO3 appears to prevent unwanted reduction/hydroboration of the alkyne prior to carborane formation, and the process is compatible with aryl, halo, hydroxy, nitrile, carbamate, and carbonyl functionalized alkynes.
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Antonio
authors.initials: A
authors.lastname: Toppino
authors.forename: Afaf R
authors.initials: AR
authors.lastname: Genady
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: El-Zaria
authors.forename: James
authors.initials: J
authors.lastname: Reeve
authors.forename: Fargol
authors.initials: F
authors.lastname: Mostofian
authors.forename: Jeff
authors.initials: J
authors.lastname: Kent
authors.forename: John F
authors.initials: JF
authors.lastname: Valliant