187344-92-9Relevant articles and documents
Synthesis of novel C2 and C1 symmetric chiraphos derivatives and their application in palladium-catalyzed miyauramichael reaction
Jin, Masayoshi,Nakamura, Masaharu
, p. 1035 - 1037 (2013)
A new method for the synthesis of C2 and C1 symmetric CHIRAPHOS derivatives and their application in Pd-catalyzed 1,4-addition reaction of an aryl boron compound to an ,￠-unsaturated carbonyl compound (MiyauraMichael reaction) are described. Six CHIRAPHOS congeners are prepared by substitution reactions of (2R,3R)-butane-2,3-diyl ditosylate with metalated phosphineborane adducts and subsequent deprotection of the resulting borane-protected bisphosphines. In the asymmetric MiyauraMichael reaction, the CHIRAPHOS derivative containing 4-tolyl groups showed a higher enantioselectivity than the others including parent CHIRAPHOS.
Development of effective bidentate diphosphine ligands of ruthenium catalysts toward practical hydrogenation of carboxylic acids
Saito, Susumu,Wen, Ke,Yoshioka, Shota
supporting information, p. 1510 - 1524 (2021/06/18)
Hydrogenation of carboxylic acids (CAs) to alcohols represents one of the most ideal reduction methods for utilizing abundant CAs as alternative carbon and energy sources. However, systematic studies on the effects of metal-to-ligand relationships on the catalytic activity of metal complex catalysts are scarce. We previously demonstrated a rational methodology for CA hydrogenation, in which CA-derived cationic metal carboxylate [(PP)M(OCOR)]+ (M = Ru and Re; P = one P coordination) served as the catalyst prototype for CA self-induced CA hydrogenation. Herein, we report systematic trial- and-error studies on how we could achieve higher catalytic activity by modifying the structure of bidentate diphosphine (PP) ligands of molecular Ru catalysts. Carbon chains connecting two P atoms as well as Ar groups substituted on the P atoms of PP ligands were intensively varied, and the induction of active Ru catalysts from precatalyst Ru(acac)3 was surveyed extensively. As a result, the activity and durability of the (PP)Ru catalyst substantially increased compared to those of other molecular Ru catalyst systems, including our original Ru catalysts. The results validate our approach for improving the catalyst performance, which would benefit further advancement of CA self-induced CA hydrogenation.
Cinchona alkali ligand and preparation method and application thereof
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Paragraph 0085-0088; 0093-0096; 0128-0129; 0134-0135; ..., (2021/12/31)
The invention belongs to the field of organic chemical ligands, and particularly relates to a cinchona alkali ligand, which has a structure shown in a general formula I or a tautomer, an enantiomer and a diastereoisomer thereof, in the formula I, R1 is selected from alkyl, alkenyl and -CH = CHPh, R2 is selected from hydrogen, alkyl, phenyl and substituted phenyl, and R is selected from substituted phenyl. The invention also discloses a preparation method and application of the cinchona alkaloid ligand. The ligand disclosed by the invention has advantages in stereoselectivity and reaction efficiency, and a higher ee value and yield can be obtained in an asymmetric reaction.
