Hoffmann-Loffler-Freytag

Radical reactions of Hoffmann-Loffler-Freytag type with participation of iodine(III) compounds leading to five-member N-heterocycles 97YGK90. 

Prior to 1958, the only well known examples of functionalization at non activated carbon atoms, in a predictable and specific manner, were those where the Hoffmann-Loffler-Freytag reaction was used. 

En route to the total synthesis of cinchona alkaloid meroquinene, a Hoffmann-La Roehe group took advantage of the Hofmann-Loffler-Freytag reaetion to funetionalize the ethyl side ehain in piperidine 49 to give ehloroethylpiperidine 51 via the intermediaey of protonated aminyl radieal 50. °... 

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