An unexpected cyclization reaction of tert-butyl o-trimethylsilylphenyl sulfoximine

Abstract

An efficient one-pot synthesis of the title compound 5 starting from methyl phenyl sulfoximine is described. On attempted iododesilylation of this compound using iodine chloride, one methyl group on the silicon atom is formally replaced by the imino nitrogen to give a derivative 8 of the novel heterocyclic system 1,3,2-benzothiasilazole.

Sulfoximine‐Directed Arene ortho‐Lithiation

“…Interestingly, at higher temperatures the N-silyl o-lithiosulfoximine 19 was not stable but suffered a N,C-silyl-lithium migration and gave the N-lithio osilylsulfoximine 22, which after protonation furnished the NÀ H o-silyl sulfoximine 24 c in 95 % yield. [14,15] Interesting results were obtained by using lithium diisopropylamide (LDA) as base for the lithiation of 15. Apparently, deprotonation of 15 with LDA led to the establishment of an equilibrium between the sulfoximine, LDA, o-lithiosulfoximine and HNiPr 2 at low temperature.…”

S-Trifluoromethyl Sulfoximine as a Directing Group in Ortho-Lithiation Reaction toward Structural Complexity

“…Among the DMGs having the strongest effect, sulfones, amides, and sulfonamides were the best candidates. Surprisingly very few examples were described with sulfoximines as DMG and, to the best of our knowledge, none with S -perfluoroalkyl sulfoximines. We were, however, fully convinced of the interest of these groups because of the presence of chelating heteroatoms associated with high electron-withdrawing properties.…”