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Trinuclear Rhodium Complexes and Their Relevance for Asymmetric Hydrogenation
Author(s) -
Preetz Angelika,
Baumann Wolfgang,
Drexler HansJoachim,
Fischer Christian,
Sun Jiangtao,
Spannenberg Anke,
Zimmer Oswald,
Hell Wolfgang,
Heller Detlef
Publication year - 2008
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200800184
Subject(s) - rhodium , relevance (law) , asymmetric hydrogenation , chemistry , combinatorial chemistry , catalysis , organic chemistry , political science , enantioselective synthesis , law
Various trinuclear rhodium complexes of the type [Rh 3 (PP) 3 ( μ 3 ‐OH) x ( μ 3 ‐OMe) 2− x ]BF 4 (where PP=Me‐DuPhos, dipamp, dppp, dppe; different ligands and μ ‐bridging anions) are presented, which are formed upon addition of bases such as NEt 3 to solvate complexes [Rh(PP)(solvent) 2 ]BF 4 . They were extensively characterized by X‐ray diffraction and NMR spectroscopy ( 103 Rh, 31 P, 13 C, 1 H). Their in situ formation resulting from basic additives (NEt 3 ) or basic prochiral olefins (without addition of another base) can cause deactivation of the asymmetric hydrogenation. This effect can be reversed by means of acidic additives.