Azirine esters, Swem oxidation

Finally, chiral 2//-azirine-2-carboxylic esters 128 can be prepared from the corresponding aziridines 127 under mild Swem oxidation conditions. This method, which is effective for both cis and trans substrates, introduces the double bond regioselectively at the "non-conjugated" site [95TL4665]. 

Chiral 2//-azirines have been prepared by dehydrochlorination of 7V-chloroaziridines, Swem oxidation of aziridines and elimination from A -sulfinylaziridines. These reactions require the use of high enantiopure aziridine esters as starting materials <03T2345>. Chiral enriched ethyl 3-methyl-2//-azirine-2-carboxylate was found to act as an efficient alkylating agent for the preparation of a variety of five-membered aromatic nitrogen heterocycles <03TL6277>. 

The Swem oxidation is also an excellent system for the oxidation of secondary amines into imines.44-46 In particular, the method is compatible with small ring systems such as azirines.47 Optically active 2//-azirine-2-carboxylie esters from the corresponding aziridines were synthesised by employing the Swem conditions and proceeded with complete retention of configuration at the C2 stereogenic centre. 

Formamides An improved proc rormic acid in combination with oxalyl chlo 2H-Azirine-2-carboxylic esters. Dc xrcurs under the Swem oxidation condition... 

H-Azirine-2-carboxylic esters. Dehydrogenation of aziridine-2-carboxylic esters occurs under the Swem oxidation conditions. 

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See also in sourсe #XX -- [ ]

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