Alkylations and thermal sigmatropic rearrangements of nickel 1-methyl-tetradehydrocorrins

Abstract

Nickel 1-methyltetradehydrocorrins react with alkyl halides to yield nickel 19-alkyl-1-methyltetradehydrocorrin salts. In one example in the analogous cobalt series the reaction is similar, although the cobalt 1-methyltetradehydrocorrin must be prepared in situ. When the nickel 1-methyltetradehydrocorrins are heated in o-dichlorobenzene, they undergo a smooth sigmatropic rearrangement to corroles containing a gem-dialkyl grouping at C-2. Similar treatment of a nickel 1-methyltetradehydrocorrin containing no alkyl substituent at C-2 gave the normal nickel corrole.