Magnesium-mediated sp³ C–H activation in cascade cyclization of 1-arylethynyl-2-alkyl-o-carboranes: efficient synthesis of carborane-fused cyclopentanes

Abstract

This work reports an unprecedented cascade cyclization of 1-arylethynyl-2-alkyl-o-carboranes promoted by magnesium-mediated sp3 C-H activation. Treatment of 1-arylethynyl-2-alkyl-o-carboranes with MeMgBr gives a series of carborane-fused cyclopentanes in very good yields....

Regioselectivity of Pd-catalyzedo-carborane arylation: a theoretical view

“…[31][32][33] The most challenging factor in broadening the applications of carboranes is the ability to perform selective functionalizations at the desired B-H or C-H vertex. 19,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] In order to give a glance of icosahedral carboranes, the number system of dicarba-closo-dodecarboranes (C 2 B 10 H 12 ) has been shown in Scheme 1(a). The electrostatic potential (ESP) surface calculation of o-carborane reveals charge separation character (Scheme 1(b)), wherein the positive charge resides mainly on B-H bonds and the negative charge resides mainly on C-H bonds.…”