Alkynyliodonium Salts as Alkynylating Reagents: Direct Conversion of Alkynylphenyliodonium Tosylates to Dialkyl Alkynylphosphonates with Trialkyl Phosphites

Article abstract of DOI:10.1021/jo00292a026

The treatment of various alkynyl(phenyl)iodonium tosylates 1 (R = t-Bu, s-Bu, i-Pr, cyclopentyl, Ph, and p-MeC6H4; X(-) = OTs(-)) with neat trimethyl phosphite gave the dimethyl alkynylphosphonates 4a and 4d-h in isolated yields ranging from 34 to 90percent.Similar treatment of 1 (R = t-Bu, X(-) = OTs(-)) with neat triethyl and triisopropyl phosphites gave the diethyl and diisopropyl alkynylphosphonates 4b (81percent) and 4c (58percent).The byproducts of these reactions are alkyl tosylates and iodobenzene.The high yields of iodobenzene, determined by GC analysis for the reactions of 1 (R = s-Bu, p-tolyl; X(-) = OTs(-)) with trimethyl phosphite, indicate that the cleavage of the alkynyl(phenyl)iodonium ions with trialkyl phosphites proceeds with high regioselectivity at the alkynyl ligand.