Palladium-catalyzed selective B(3)–H arylation of o-carboranes with arylboronic acids at room temperature

Abstract

A palladium-catalyzed selective B(3)–H arylation of o-carboranes under room temperature has been developed using readily available arylboronic acids as the aryl source, and the corresponding 3-aryl-o-carboranes were obtained in good to excellent yields.

Directing-Group-Assisted Transition-Metal-Catalyzed Selective BH Functionalization of o-Carboranes

“…The Lu group accomplished a Pd-catalyzed regioselectivity B(3)-arylation through reaction of 1-pyridyl-o-carborane 177 with arylboronic acids using Ag 2 O as oxidant (Scheme 42). 59 Arylboronic acids with various substituents such as halo, aldehyde, ketone, ester, cyano, and nitro groups, worked well to yield a series of 1-pyridyl-3-aryl-ocarboranes 188 in high yields with good mono-selectivity. An unsymmetrical B(3,6)-arylated product 189 was obtained via stepwise arylation.…”

Iridium-catalyzed selective arylation of B(6)–H of 3-aryl-o-carboranes with arylboronic acid via direct B–H activation

“…9 According to this oxidative coupling strategy, the selective arylation of B(3)–H with arylboronic acid assisted with directing groups was developed by the Lin group and Lu group. 10 However, employing arylboronic acid for selective arylation of B(3,6)–H via direct B–H activation has not been reported yet. In connection with our continuing interest in the selective functionalization of the B–H bond of o -carboranes, herein, we are pleased to disclose an iridium-catalyzed selective arylation of B(6)–H of o -carboranes with arylboronic acid via direct B–H activation (Scheme 1c).…”

Breaking the Base Barrier: Cu(II)-Mediated C–H Heteroarylation of o-Carboranes with Base-Sensitive Heteroaryl Halides

“…However, base-metal-promoted cage C–H functionalization is still rare . Within our program on cage C-functionalization, we wondered whether the combination of base metal catalysis and a weak base would allow us to achieve cage C–H (hetero)­arylation. Numerous challenges have hampered the development of a general method for strong base-free cage C-heteroarylation (Scheme C).…”