The intramolecular sila-Pummerer cyclization: A new route to sulfur heterocycles

The generality of the intramolecular cyclization of suitable nucleophilic sites to a  S⁺CH₂ center created by a sila-Pummerer rearrangement has been investigated. Successful nucleophilic sites included the OH group (in alcohols, carboxylic acids, and hydroxylamines) and the NH group (in amines and carbamates): attempts to produce carbon-based nucleophilic sites were not effective. Successful cyclizations were achieved to produce sulfur heterocycles with 5-, 6-, and 7-membered rings.