ChemInform Abstract: TRANSFER HYDROGENATION AND TRANSFER HYDROGENOLYSIS. IX. HYDROGEN TRANSFER FROM ORGANIC COMPOUNDS TO ALDEHYDES AND KETONES CATALYZED BY DIHYDRIDOTETRAKIS(TRIPHENYLPHOSPHINE)RUTHENIUM(II)

1976 ◽  
Vol 7 (22) ◽  
pp. no-no
Author(s):  
H. IMAI ◽  
T. NISHIGUCHI ◽  
K. FUKUZUMI
Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1165
Author(s):  
Yasuhiro Sato ◽  
Yuichi Kawata ◽  
Shungo Yasui ◽  
Yoshihito Kayaki ◽  
Takao Ikariya

As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C–N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2′-bis(aminomethyl)-1,1′-binaphthyl (1) from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH4. The reaction of (S)-1 with an equimolar amount of [IrCl2Cp*]2 (Cp* = η5–C5(CH3)5) in the presence of sodium acetate in acetonitrile at 80 °C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes (5) through the double C–H bond cleavage, as confirmed by 1H NMR spectroscopy. A loss of the central chirality on the Ir centers of 5 was demonstrated by treatment with KOC(CH3)3 to generate the corresponding 16e amidoiridium complex 6. The following hydrogen transfer from 2-propanol to 6 provided diastereomers of hydrido(amine)iridium retaining the bis(azairidacycle) architecture. The dinuclear chlorido(amine)iridium 5 can serve as a catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with a substrate to a catalyst ratio of 200 in the presence of KOC(CH3)3 in 2-propanol, leading to (S)-1-phenylethanol with up to an enantiomeric excess (ee) of 67%.


1989 ◽  
Vol 21 (4) ◽  
pp. 515-517 ◽  
Author(s):  
Dimitris M. Spyriounis ◽  
George Ikonomidis ◽  
Vassilis J. Demopoulos

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