AROMATIC-SUBSTITUTION .58. BORON TRIS(TRIFLATE) CATALYZED ADAMANTYLATION OF BENZENE AND TOLUENE WITH 1-HALOADAMANTANES AND 2-HALOADAMANTANES AND ADAMANTANOYL CHLORIDES - ISOMERIZATION OF PHENYLADAMANTANES AND TOLYLADAMANTANES

Boron tris(triflate) catalyzed adamantylation of benzene and toluene was studied with isomeric 1- and 2-haloadamantanes. The alkylations give 1- and 2-phenyl- and isomeric tolyladamantanes in varying ratios. Interconversion of isomeric 2-phenyl(tolyl)adamantanes into the corresponding l-phenyl(tolyl)adamantanes was observed through intermolecular isomerization involving adamantyl cations and adamantane, which is formed in significant amount in all the reactions. Decarbonylative alkylation of aromatics with adamantanoyl chlorides was also investigated. Adamantanoylated aromatics were formed only in very low amounts, the major product being adamantylated aromatics in accord with extensive decarbonylation of the adamantanoyl cations. The mechanism of the studies adamantylations was further substantiated by studying the boron tris(triflate) catalyzed isomerization of 1- and 2-aryladamantanes under comparable conditions. © 1990, American Chemical Society. All rights reserved.