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Sulfinamides were synthesized from sulfonyl chlorides using a procedure involving the in situ reduction of sulfonyl chlorides. The reaction is broad in scope and easy to perform.Sulfinamides, especially chiral sulfinamides, play vital roles in the modern asymmetric chemistry. 1 Furthermore, sulfinamides can also act as N-sulfinyl protecting group in ease of removal under mild conditions. 2 Even though there are various procedures reported for the preparation of sulfinamides from sulfinic acids 3 , sulfinates 4 , sulfinyl chlorides 5 , disulfides 6 , and homolytic substitution at the sulfur atom 7 , these reactions often require two or more synthetic steps. A one-step process would be useful and increase the exploration of sulfinamide chemistry.Sulfinamides are useful compounds and can be transformed to a number of other important functional groups. 8 For example, they can be converted to sulfonimidoyl chlorides, whose chemistry is both interesting and useful. 9 We reported that benzothiazines can be prepared from N-aryl sulfinamides by oxidation with t-butyl hypochlorite and subsequent treatment with an alkene or alkyne in the presence of a Lewis acid. (Scheme 1). 10 The requisite sulfinamide was prepared from a sulfinyl choride in high yield. While sulfinyl chlorides are not exceptionally difficult to make, they are sensitive to hydrolysis and require preparation using noxious reagents such as thionyl chloride. We thought that a procedure to quickly access sulfinamides would be useful in both exploring sulfinamide chemistry and derivatives such as sulfonimidoyl chlorides.A number of years ago Sharpless 11 reported the synthesis of sulfinate esters from sulfonyl chlorides by a one-pot reductive esterification reaction using either phosphites as the reducing agent. Attempts to prepare sulfinamides by the Sharpless group were not successful. We thought however, that the modification of the synthesis of sulfinate esters introduced by Toru 12 , which used triarylphophines as the reductant, would be suitable for the synthesis of such compounds. This letter reports the realization of that idea.We began our studies by simply using Toru's procedure for sulfinate ester formation. 11 The results are summarized in Table 1. When a CH 2 Cl 2 solution of triphenylphosphine was added to the mixture of TsCl, TEA (10 equivalents) and BzNH 2 in CH 2 Cl 2 at 0 °C, only sulfonamide 6 and PPh 3 were detected by the NMR analysis of the crude mixture (entry 1). However, a small change in the addition sequence offered an encouraging result. When PPh 3 and benzylamine in CH 2 Cl 2 were added to a mixture of triethylamine and tosyl chloride, the desired HarmataM@Missouri.edu. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript sulfinamide was isolated in 62% yield, (entry 2). Only a 14% yield of sulfinamide, accompanied by 40% sulfonamide, was isolated when the reaction was performed by the addition of PPh 3 to TsCl in CH 2 Cl 2 over 1 hour followed by addition of a mixture of BzNH 2 and T...

The reaction of S-2-bromophenyl-S-methylsulfoximine with terminal alkynes in the presence of a palladium catalyst resulted in the formation of both 1,2-benzothiazines and 1,2-benzoisothiazoles. A preference for the former was seen with alkylalkynes, while the latter were preferentially formed with alkynylarenes.

A reactive cyclopentadienone gives Diels–Alder cycloadducts with a variety of dienes in high yield and often with extremely high levels of regio‐ and stereoselectivity. The high degree of generality of this reaction suggests it will be of use in organic synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)