Amine oxides sulfamides

This brief discussion on the synthetic utihty of oxathiazinanes is only intended to highhght the versatihty of these reagents. Readers who seek a more detailed review on the chemistry of sulfamidites and sulfamidates are referred to a recent, comprehensive account by LubeU [121]. Apphcations for these unusual heterocychc building blocks should see continued growth with the oxidative amination technologies now available for their preparation. 

The traditional synthesis of cyclic sulfimidates from /3-aminoalcohols and SOCl2 in the presence of amine as a base has been developed further to the preparation of the enantiopure monocyclic as well fused sulfimidates (Schemes 26 and 27). 1,2,3-Oxathiazolidine mono-.Y-oxides are readily oxidized to corresponding sulfamidates by RuCR and NalCb, and the synthesis of sulfamidates can be performed in a one-pot procedure from -aminoalcohols without isolation of intermediate sulfimidates (Equation 37). The reaction of sulfamate esters 145 with PhI(OAc)2 and various catalysts proved to be a reliable method for the enantioselective preparation of cyclic sulfamidates 146 (Equation 35). 

A simple, efficient synthesis of 4-substituted 1,2,4,6-thiatriazine 1,1-dioxides involves reacting 0,0 -diaryl carbonimidates with thionyl chloride and triethylamine to give sulfoxides which are oxidized with MCPBA. The resulting sulfamides are then reacted with primary amines to give the required products (Scheme 9) <87S170>. 

C-H Amination. A number of amine-based starting materials will react with PhI(OAc)2 and a transition metal catalyst to promote selective C-H bond amination. Intramolecular oxidation of substrates such as carbamates, ureas, sulfamates, sulfonamides, and sulfamides affords the corresponding heterocycles in high yields and, in many cases, with excellent diastereocontrol (eqs 60 and 61). Insertion into optically active 3° C-H centers is reported to be stereospecific (eq 62). Chiral Ru, Mn, and Rh catalysts have all been utilized for asymmetric C-H amination, though product enantiomeric induction is variable. Many of the heterocyclic structures furnished from these reactions function as versatile precursors to 1,2- and 1,3-amine derivatives. 

In 2001, Du Bois and co-workers developed the intramolecular amination of diverse C—H bonds, including aliphatic ones, by employing the commercially available Rh-catalyst [Rh2(OAc)4] and oxidant PhI(OAc)2. Inspired by this work, Muller and co-workers realized intra- and intermolecular amidation reactions by in situ formed nitrene species. Employing the chiral dirhodium Rh2(S-NTTL)4 developed by their group, cyclic sulfamidates 104 were synthesized in good yields and stereocontrol with sulfamates 103 and PhI(OAc)2 as the nitrene precursors (Scheme 1.37). Subsequently, they... 

C—H amination reactions via oxidation with a hypervalent iodine reagent are also possible with sulfamates [44]. The formation of the 5-membered sulfamidate is only observed if no alternative cydization pathway is available (Eq. (5.10)). 

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