Novel Selective Iodinating Reagent

N,N-Dimethyl-N-(methylsulfanylmethylene)ammonium iodide developed by Porter et al. is a novel selective iodinating reagent, which can convert primary and secondary alcohols to the corresponding iodo compounds. In particular, primary alcohols react more rapidly than secondary alcohols, which allows selective iodination of primary hydroxy groups or in primary-secondary diols.