18867-43-1Relevant articles and documents
Diamine-Tethered Bis(thiourea) Organocatalyst for Asymmetric Henry Reaction
Otevrel, Jan,Bobal, Pavel
, p. 8342 - 8358 (2017/08/23)
We have developed a novel multifunctional C2-symmetric biphenyl-based diamine-tethered bis(thiourea) organocatalyst, which was tested in the asymmetric Henry reaction. Under thoroughly optimized conditions, the catalyst provided exceptionally high yields and excellent enantioselectivities especially for electron-deficient aromatic and heterocyclic substrates. Due to a high affinity of the catalyst to silica gel, a simple chromatography-free nitroaldol isolation procedure was feasible. Preliminary kinetic and spectroscopic experiments were performed in order to complete the mechanistic picture of the organocatalyzed nitroaldolization process. Finally, the developed synthetic strategy was successfully applied to the catalytic enantioselective syntheses of enantiopure (S)-econazole and (R)-mirabegron a late-stage intermediate.
Preparation of axially chiral biphenyl diphosphine ligands and their application in asymmetric hydrogenation
Morimoto, Toshiaki,Yoshikawa, Kiyoshi,Murata, Masanao,Yamamoto, Naoko,Achiwa, Kazuo
, p. 1445 - 1450 (2007/10/03)
Axially chiral biphenyldiphosphine ligands bearing diphenylphosphino group(s) and/or dicyclohexylphosphino group(s) were prepared in enantiomerically pure form starting from 2,6-dimethylnitrobenzene via 8 steps: iodination, reduction, methoxylation throug
Asymmetric Hydrogenation of α, β, and γ-Aminoketones Catalyzed by Cationic Rhodium(I){AMPP} Complexes
Devocelle, Marc,Agbossou, Francine,Mortreux, André
, p. 1306 - 1308 (2007/10/03)
The chiral cationic rhodium aminophosphine-phosphinite complexes 4-6 were applied successfully in the asymmetric hydrogenation of α- (7-9), β- (10, 11) and γ- (12) aminoketone hydrochloride derivatives leading to the corresponding aminoalcohols in up to 9
Efficient asymmetric hydrogenation of α-amino ketone derivatives. A highly enantioselective synthesis of phenylephrine, levamisole, carnitine and propranolol
Sukuraba,Takahashi,Takeda,Achiwa
, p. 738 - 747 (2007/10/02)
The complexes of pyrrolidine bisphosphine ligands (CPMs) with rhodium (I) were found to be efficient catalysts for asymmetric hydrogenation of α-amino ketone hydrochloride derivatives. Utilizing this methodology, we have developed efficient asymmetric syntheses of the optically active β-amino alcohols, phenylephrine, levamisole, carnitine and propranolol.
A new type of atropisomeric biphenylbisphosphine ligand, (R)-MOC-BIMPO and its use in efficient assymetric hydrogenation of α-aminoketone and itaconic acid
Yoshikawa,Yamamoto,Murata,Awano,Morimoto,Achiwa
, p. 13 - 16 (2007/10/02)
A new atropisomeric biphenylbisphosphine, MOC-BIMOP, has been prepared in enantiomerically pure form and its rhodium(I) complex proved to be an efficient catalyst in the asymmetric hydrogenations of α-aminoketone hydrochloride and itaconic acid. A possibl
Development of new 6-membered chelating chiral bisphosphine ligands for rhodium-catalyzed asymmetric hydrogenation
Inoguchi,Fujie,Yoshikawa,Achiwa
, p. 2921 - 2926 (2007/10/02)
A new chiral 1,3-bisphosphine, (1R,2R)-1-diphenylphosphino-2-(diphenylphosphinomethyl)cyclopentane, which was designed to form the favorable skew conformation of the six-membered chelate with rhodium, was developed. Its rhodium complex was found to be one of the most efficient catalysts known for asymmetric hydrogenation of amino acid precursors. Further improvement of this ligand was also attempted for catalytic asymmetric hydrogenation of prochiral ketones to clarify the enantioselective mechanism.
The Cyclic Dipeptide cyclo as a Catalyst for Asymmetric Addition of Hydrogen Cyanide to Aldehydes
Tanaka, Kenzo,Mori, Atsunori,Inoue, Shohei
, p. 181 - 185 (2007/10/02)
cyclo (cyclo, 1) catalyzes the addition of hydrogen cyanide to benzaldehyde in toluene at -20 deg C to afford (R)-mandelonitrile with enantiomeric excess of 97 percent in high yield. cyclo gives (S)-mandelonitrile. cyclo (1) exhibits a broad substrate specificity, and a variety of aldehydes (3a-r) such as m-methoxybenzaldehyde (3c), 6-methoxy-2-naphthaldehyde (3k), and isobutyraldehyde (3o) similarly afforded the corresponding cyanohydrins with high enantiopurities (97 percent ee for 3c, 93 percent ee for 3k, 71 percent ee for 3o). (R)-Mandelonitrile thus obtained was successfully converted to various chiral synthons such as mandelic acid (7), methyl mandelate (8), and 2-amino-1-phenylethanol (9) without any racemization.