Reaction of 13-vertex carborane μ-1,2-(CH2)3-1,2-C2B11H11 with nucleophiles: scope and mechanism.

13-Vertex carborane, μ-1,2-(CH(2))(3)-1,2-C(2)B(11)H(11) (1), reacted with a series of nucleophiles (Nu) to give the cage carbon extrusion products μ-1,2-(CH(2))(3)CH(Nu)-1-CB(11)H(10), μ-1,2-(CH(2))(2)CH(Nu)CH(2)-1-CB(11)H(10), and/or μ-1,2-(CH(2))(2)CH═CH-1-CB(11)H(10), depending on the nature of Nu and the reaction conditions. The key intermediates for the formation of CB(11)(-) anions were isolated and structurally characterized as μ-η:η:η-7,8,10-(CH(2))(3)CHB(Nu)-7-CB(10)H(10) (Nu = OMe, NEt(2)). The reaction mechanism is thus proposed, which involves the attack of Nu at the most electron-deficient cage boron, followed by H-migration to one of the cage carbons, leading to the formation of the intermediate. Nu-migration gives the products.