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Diamination of Olefins: Synthesis, Structures and Reactivity of Osmaimidazolidines
Author(s) -
Muñiz Kilian,
Iesato Atsushi,
Nieger Martin
Publication year - 2003
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.200305011
Subject(s) - dihydroxylation , osmium , olefin fiber , reactivity (psychology) , chemistry , catalysis , enantioselective synthesis , organic chemistry , combinatorial chemistry , computational chemistry , ruthenium , medicine , alternative medicine , pathology
The diamination of certain olefins bearing electron‐withdrawing substituents proceeds with well‐defined bisimido and trisimido complexes of osmium. The products are obtained as osmaimidazolidines which are of unprecedented stability with regards to olefin functionalisation. Osmium complexes from related dihydroxylation or aminohydroxylation are significantly less stable and thereby promote catalytic reactions. This difference in reaction profile has been investigated and chiral osmium heterocycles obtained from olefin difunctionalisation were characterised by X‐ray analysis for the first time. Kinetic studies on the reaction profile have also been carried out. An asymmetric version of this reaction is based on chiral non‐racemic auxiliaries and leads to diastereomerically enriched osmaimidazolidines with up to 90 % de. This sequence represents the first asymmetric diamination of olefins. Attempts on the use of chiral ligands for direct asymmetric diamination as well as the consequences of osmaimidazolidine properties for a catalytic reaction are discussed.