Sulfur-Based Protecting Groups for Pyrroles and the Facile Deprotection of 2-(2,4-Dinitrobenzene)sulfinyl and Sulfonyl Pyrroles ThompsonAlison ButlerR. Jonathan GrundyMeaghan N. LaltooAndrea B. E. RobertsonKatherine N. CameronT. Stanley 2005 The effectiveness of simple sulfinyl and sulfonyl groups as electron-withdrawing protecting groups for pyrroles has been analyzed using <sup>13</sup>C NMR spectroscopy and confirmed by consideration of X-ray crystal structures. Additionally, the 2,4-dinitrobenzenesulfinyl and sulfonyl groups are shown to be effective electron-withdrawing protecting groups for pyrroles, and they can be removed by treatment with benzene thiol or thiolate under mild and specific conditions.