Premium
Dehydrogenation of Hydridoirida‐β‐diketones in Methanol: The Selective Formation of Mono‐ and Dinuclear Acyl Complexes
Author(s) -
Ciganda Roberto,
Garralda María A.,
Ibarlucea Lourdes,
Mendicute Claudio,
Pinilla Elena,
Torres M. Rosario
Publication year - 2010
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201000250
Subject(s) - chemistry , dehydrogenation , cyclohexanone , cyclohexanol , medicinal chemistry , pyridine , methanol , cationic polymerization , crystal structure , catalysis , stereochemistry , polymer chemistry , organic chemistry
The hydridoirida‐β‐diketone [IrH{(PPh 2 ( o ‐C 6 H 4 CO)) 2 H}Cl] ( 1 ) reacts with diimines (NN) or with pyridine (py) in refluxing methanol to undergo dehydrogenation. The reactions afford selectively the cis ‐acyl, trans ‐phosphane isomers of the cationic [Ir(PPh 2 ( o ‐C 6 H 4 CO)) 2 (NN)] + {NN = 2,2′‐bipyridine ( 2 ); R–N=C(CH 3 )–C(CH 3 )=N–R′ [R = R′ = NH 2 ( 3 ); R = R′ = OH ( 4 ); R = OH, R′ = NH 2 ( 5 )]} or neutral [IrCl(PPh 2 ( o ‐C 6 H 4 CO)) 2 (py)] ( 6 ) derivatives. The reactions are faster for ligands containing amino substituents. Refluxing 1 in MeOH affords the formation of an equimolar mixture of dimercationic species [Ir 2 (μ‐Cl)(μ‐PPh 2 ( o ‐C 6 H 4 CO)) 2 (PPh 2 ( o ‐C 6 H 4 CO)) 2 ] + ( 7a and 7b ) containing two acyls and a chloride as bridging groups. The isomers could be separated by fractional precipitation. Compound [ 3 ]Cl, containing amino substituents in the imino functionalities, catalyses the hydrogen transfer from 2‐propanol to cyclohexanone to afford cyclohexanol. All the complexes were fully characterised spectroscopically. Single crystal X‐ray diffraction analysis was performed on complexes 6 and [ 7b ]ClO 4 .