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Alpha‐ and Beta‐Diastereoisomers of Phenylcobalamin from Cobalt‐Arylation with Diphenyliodonium Chloride
Author(s) -
Brenig Christopher,
Ruetz Markus,
Kieninger Christoph,
Wurst Klaus,
Kräutler Bernhard
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201701514
Subject(s) - chemistry , sodium borohydride , aryl , diastereomer , cobalamin , cobalt , sodium formate , formate , medicinal chemistry , combinatorial chemistry , stereochemistry , catalysis , organic chemistry , biochemistry , alkyl , vitamin b12
Organometallic aryl‐cobalamins are B 12 ‐derivatives featuring properties of potential ‘B 12 antivitamins’. Herein, we describe a new method for the preparation of aryl‐cobalamins using versatile diaryliodonium salts as arylation agents. Formate or sodium borohydride reduction of aquocobalamin in presence of diphenyliodonium chloride furnished Co β ‐phenyl‐cobalamin PhCbl in a roughly 3:1 to 1:1 ratio with its coordination isomer αPhCbl , a first representative ‘base‐off’ Co α ‐aryl‐cobalamin. The new structures were secured by detailed spectroscopic analysis, supplemented by an X‐ray crystal structure analysis of PhCbl . Both types of coordination isomers of the aryl‐cobalamins promise to be useful molecular tools in biomedical and biological studies.