Generation and trapping reaction of an efficient 1,2-dehydrocarborane precursor, phenyl[o-(trimethylsilyl)carboranyl]iodonium acetate

Abstract

An efficient 1,2-dehydrocarborane precursor, phenyl[o-(trimethylsilyl)carboranyl]iodonium acetate 4, was readily prepared by reaction of [o-(trimethylsilyl)carboranyl]lithium and IPh(OAc)₂. The facile 2+4 cycloaddition of 4 with dienes such as anthracene, naphthalene, norborna-2,5-diene and 2,5-dimethylfuran gave high yields of the 1,2-dehydrocarborane adducts in the presence of a desilylating agent. The reaction of 4 with a cyclic alkene and strained cycloalkynes afforded the adducts formed by the ene reaction and the 2+2 cycloaddition reaction. The reaction of 2 with a bicyclopalladacycle yielded the cyclization product. The structures of compounds 5 and 7 were determined by single-crystal X-ray crystallography.