Selenium-Chloramine

The full paper on the synthesis of D-forosamine(4-dimethylamino-2,3,4,6-tetradeoxy-D- ryz/rro-hexose) from (2) has also appeared. Standard transformations have been used in a synthesis of derivatives of L-ristosamine (3-amino-2,3,6-trideoxy-L-ara6i/ >-hexose), and its C-4 epimer, from l-rhamnal. Non-carbohydrate precursors have been utilized for the synthesis of the derivative (3) of racemic daunosamine (3-amino-2,3,6-trideoxy-/j xo-hexose), in a sequence involving allylic amination of a hexenal derivative using a selenium-chloramine T reagent, followed by m-hydroxylation which led to a crystalline product with the required lyxo configuration (Scheme 2). ... 

Bis(4-toluenesulphonyl)selenodiimide (TosN=Se=NTos), prepared from Chloramine T and metallic selenium, reacts with olefins by insertion at the more substituted allylic... 

This approach is used exclusively for the synthesis of the isomeric annelated isothiazoles and isoselenazoles to form the nitrogen-sulfur(selenium) bond and has been discussed in CHEC-II(1996) <1996CHEC-II(7)49>. A wide variety of oxidative cyclizations have been reported, some of which incorpotate an amination. Eor example, reaction of 47 with chloramine gives the corresponding isothiazolo[5,4-7]thiophene 40 (Equation 9) <2000P65>. 

Bis[N-(p-Toluenesulfonyl)]selenodiimide. The reagent obtained from the reaction of chloramine-T with selenium metal, proposed to have structure TsN=Se=NTs, reacts with TIPS enol ethers in an ene-like reaction to give the corresponding a-tosylamino enol ethers (see Eq. 100).345-349... 

Allylic animation. The reaction of selenium metal with 2 equiv. of anhydrous chloramine-T (TsNCINa) in CH2CI2 gives a solution of a reagent formulated as (1). A similar, but less reactive, reagent is formed by reaction of selenium tetrachloride with p-toluencsulfonamide. The reagent reacts with alkenes at 20°... 

Preparative Methods selenium metal is allowed to react with 2 equiv of anhydrous chloramine-T (TsNClNa) in CHCI2 under N2 for 24 h. Also prepared by adding an ether solution of 7V,7V bis(trimethylsilyl)-/>toluenesulfonamide to an ether solution of selenyl chloride and stirring for 3 h. ... 

Selenium di-imides (132) were formed in methylene chloride solution from selenium tetrachloride with t-butylamine or sulphonamides and also from selenium metal with anhydrous Chloramine-T. They were found to be efficient reagents for the allylic amination of alken and alkynes. The first examples of selenium imides (133) were synthesized from diaryl selenides and Chloramine-T, from... 

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