[60123-29-7] · C14H14N2O4S2Se · Bis[N-(p-toluenesulfonyl)]selenodiimide · (MW 417.36)
Physical Data: mp 115-117 °C.
Preparative Methods: Selenium metal is allowed to react with 2 equiv of anhydrous Chloramine-T (TsNClNa) in CHCl2 under N2 for 24 h.1 Also prepared by adding an ether solution of N,N-bis(trimethylsilyl)-p-toluenesulfonamide to an ether solution of selenyl chloride and stirring for 3 h.3
Handling, Storage, and Precautions: readily hydrolyzed by water; must be kept rigorously dry.
The title compound (1) effects allylic amination of alkenes (eq 1)1 and alkynes (eq 2).1 The reaction occurs via an initial ene reaction to form (2) followed by a [2,3]-sigmatropic rearrangement. Nitrogen insertion takes place without net rearrangement of the double bond and generally occurs at the most substituted allylic position (eq 3).1
Compound (1) has been utilized in the total synthesis of gabaculine (6).4 Upon treatment with (1), alkene (3) afforded a mixture of allylic amine derivatives (4) and (5) in 45% yield (eq 4). Compound (1) has also been used effectively in the syntheses of both b-apopicropodophyllin analogs5 and daunosamine analogs.6
Trialkylsilyl enol ethers have also been aminated by (1), providing access to a-amino ketone derivatives (eq 5).7 The products of the amination have the NHTs group in an axial orientation due to interactions between the p orbital and the s* orbital of the C-N bond.8 Compound (1) was used to aminate silyl enol ether (7) in the synthesis of the benzomorphanone core structure (8) (eq 6).9
Compound (1), prepared from selenium oxychloride (9) and N,N-bis(trimethylsilyl)toluenesulfonamide (10) (eq 7), has been isolated and utilized in [4 + 2] cycloaddition reactions with dienes.3 For example (1) reacts regioselectively with isoprene to yield 3,6-dihydro-1,2-selenazine (11) (eq 8).3
In cases where (1) is prepared from chloramine T, the reaction with 1,3-dienes directly produces 1,2-disulfonamides (eq 9)2 rather than Diels-Alder adducts. Initially, the [4 + 2] adduct (12) is probably formed, which is then cleaved by traces of p-toluenesulfonamide to afford (13). This intermediate subsequently undergoes [2,3]-sigmatropic rearrangement to (14), which hydrolyzes in situ to yield disulfonamide (15). It has been suggested that the reagent prepared from selenium and chloramine T is actually (TsNNa)2SeCl2.10 Cyclic dienes afford exclusively the cis-1,2-disulfonamides (eq 10).2
Compound (1) has been used to prepare 3-vinyl-1,2,5-selenadiazole (17) from 1,2-diamine (16) via a cyclocondensation reaction (eq 11).11
Steven M. Weinreb & Geoffrey R. Heintzelman
The Pennsylvania State University, University Park, PA, USA