Aryne Insertion Reactions into σ-Bonds

Arynes were found to be utilizable as unsaturated hydrocarbons in the insertion reactions into sigma-bonds. Nitrogen-silicon (aminosilane), halogen-carbon (acid halide) and carbon-phosphorus bonds (phosphorylacetonitrile), as well as strain-free carbon-carbon bonds of active methylene compounds and fluorene derivatives were easily cleaved and added across arynes via electrophilic coupling of arynes with in situ-generated carbanions. Furthermore, total synthesis of cytosporone B and phomopsin C was accomplished by using the C-C bond cleavage reaction. In the presence of transition metal catalysts, arynes could also be inserted into tin-tin (distannane), boron-boron (diboron), carbon-bromine (alkynyl bromide) and carbon-hydrogen bonds, (terminal alkyne).