Iodine(III)‐Mediated Preparations of Nitrogen‐Containing Sulfur Derivatives: Dramatic Influence of the Sulfur Oxidation State

Abstract

Reaction of sulfonamides with iodosobenzene leads to phenyliodinanes. A new catalysis reaction of the decomposition of these products in the presence of sulfoxides that allows the smooth synthesis of sulfoximines has been evidenced and studied: copper(II) salts were used to prepare compounds 4 a-j and 5 b, d, f, j, k from the corresponding, easily prepared, sulfoxides. The reactions proceed with retention of configuration at the sulfur center, and copper(II) triflate is the best candidate for the catalyst for the imination. Switching from sulfonamides to sulfinamides in the preparation of the starting iodinanes completely alters the reaction pathway: iodinanes are no longer accessible, and sulfonimidates 7 a-j are obtained instead. This behavior can be rationalized by the increase in pK(a) brought about by the removal of one oxygen atom from the sulfur center. Sulfonimidates are interesting molecules with varied applications. Optimization of their one-pot synthesis has been achieved by carrying out the reaction in acetonitrile. The stereochemical study has shown that the transformation proceeds with global retention of the configuration at the sulfur center, albeit with erosion of the enantiomeric purity. A model accounting for this outcome is proposed. In addition, the presence of oxidized sulfonamide by-products has been explained, and this latter pathway becomes the sole one when alcohol is replaced by water. Good yields of the oxidized products are obtained.

Chiral Sulfur Functional Groups as Definers of the Chirality at the Metal in Ir and Rh Half‐Sandwich Complexes: A Combined CD/X‐ray Study

“…To complete our study of the use of 1,2,3‐triazole‐containing chiral sulfur groups in the generation of chiral‐at‐metal complexes, we also tested triazolium salts that had enantiopure sulfoximine groups 13 . Salts 13 were prepared from the enantiopure triazoles 4 by reaction with PhI=NTs in the presence of Cu(OTf) 2 to form N ‐tosylsulfoximinoyl triazoles 14 , which were methylated with Me 3 OBF 4 . This sequence of reactions produced the desired triazolium salts 13 in good yields.…”

“…To complete our study of the use of 1,2,3-triazole-containing chiral sulfur groups in the generation of chiral-at-metal complexes,w ea lso tested triazolium salts that had enantiopure sulfoximine groups 13.S alts 13 were prepared from the enantiopure triazoles 4 by reactionw ith PhI=NTsi nt he presence of Cu(OTf) 2 [19] to form N-tosylsulfoximinoyl triazoles 14,w hich were methylated with Me 3 OBF 4 .T his sequence of reactions produced the desired triazolium salts 13 in good yields. Triazolium salt 13 bb was reactedw ith Ag 2 Of ollowed by transmetallation with [IrCl 2 Cp*] 2 ;a gain, am ixture of complexes 15 bb and CÀH-activated 16 bb (1:3)w ere obtained and submitted to columnchromatography (SiO 2 )t oi solate the enantiopure complex 16 bb in 53 %y ield.…”

Geminal Bis(sulfoximine)s: Synthesis and Applications in Asymmetric Catalysis

“…The most prominent representatives here are mesitylenesulfonylhydroxylamine (MSH), [51] BOC azide, [52] N-aminophthalimide, [53,54] or N-tosyliminophenyliodinane. [55] Hydrazoic acid itself is less appropriate due to its incomplete stereoselectivity.…”

Formation of Cyclic Sulfinates and Sulfinamides through Homolytic Substitution at the Sulfur Atom

“…As part of our program devoted to new reactions involving sulfur-based moieties, [27][28][29][30] we became interested in the synthesis of cyclic sulfinates and sulfinamides because they are versatile synthetic intermediates, [31,32] and have elicited interest in medicinal chemistry. [33,34] They have also been used in materials science as imaging agents.…”