Premium
Catalytic Aerobic Dehydrogenative Coupling of Primary Alcohols and Water to Acids Promoted by a Rhodium(I) Amido N‐Heterocyclic Carbene Complex
Author(s) -
Annen Samuel,
Zweifel Theo,
Ricatto Federica,
Grützmacher Hansjörg
Publication year - 2010
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201000100
Subject(s) - chemistry , carbene , amide , deprotonation , rhodium , medicinal chemistry , catalysis , hydride , ligand (biochemistry) , stereochemistry , trigonal bipyramidal molecular geometry , crystal structure , photochemistry , crystallography , hydrogen , organic chemistry , ion , biochemistry , receptor
The amino diolefin complex [Rh(trop 2 NH)(TMIY)] + (OTf) − (OTf − =CF 3 SO 3 − ; trop=5‐H‐dibenzo[a,d]cyclohepten‐5yl), incorporating N‐heterocyclic carbene ligand 1,3,4,5‐tetramethylimidazole‐2‐ylidene (TMIY), has been prepared. The structure is determined by single‐crystal X‐ray diffraction, which shows a butterfly structure with the NH and TMIY groups in the apical and the two olefinic binding sites in the equatorial position of a trigonal bipyramid with one vacant site in the equatorial plane. This complex can be deprotonated to give the amide [Rh(trop 2 N)(TMIY)], which cleaves H 2 heterolytically across the RhN bond to give the amino hydride [RhH(trop 2 NH)(TMIY)]. In dimethylsulfoxide (DMSO), both the amide and amino hydride complexes are active as catalysts in the dehydrogenative coupling (DHC) of various primary alcohols with water to give the corresponding acids under aerobic conditions. O 2 serves as hydrogen acceptor. One O atom is converted into water while the other is transferred to DMSO as oxygen acceptor, to yield Me 2 SO 2 . Hence, the net reaction RCH 2 OH+2 O 2 +2 DMSO→RCOOH+2 Me 2 SO 2 +H 2 O is catalyzed by the butterfly‐shaped rhodium amide complexes.