1026995-71-0Relevant articles and documents
Cleavage of N-H Bond of Ammonia via Metal-Ligand Cooperation Enables Rational Design of a Conceptually New Noyori-Ikariya Catalyst
Dub, Pavel A.,Matsunami, Asuka,Kuwata, Shigeki,Kayaki, Yoshihito
, p. 2661 - 2677 (2019)
The asymmetric transfer hydrogenation (ATH) of ketones/imines with Noyori-Ikariya catalyst represents an important reaction in both academia and fine chemical industry. The method allows for the preparation of chiral secondary alcohols/amines with very good to excellent optical purities. Remarkably, the same chiral Noyori-Ikariya complex is also a precatalyst for a wide range of other chemo- and stereoselective reductive and oxidative transformations. Among them are enantioselective sulfonamidation of acrylates (intramolecular aza-Michael reaction) and carboxylation of indoles with CO2. Development of these catalytic reactions has been inspired by the realized cleavage of the N-H bond of sulfonamides and indoles by the 16e- amido derivative of the 18e- precatalyst via metal-ligand cooperation (MLC). This paper summarizes our efforts to investigate N-H bond cleavage of gaseous ammonia in solution via MLC and reports the serendipitous discovery of a new class of chiral tridentate I3[N,N′,N″] Ru and Ir metallacycles, derivatives of the famous M-FsDPEN catalysts (M = Ru, Ir). The protonation of these metallacycles by strong acids containing weakly coordinating (chiral) anions generates ionic complexes, which were identified as conceptually novel Noyori-Ikariya precatalysts. For example, the ATH of aromatic ketones with some of these complexes proceeds with up to 99% ee.
Ru-catalyzed asymmetric transfer hydrogenation of α-acyl butyrolactone via dynamic kinetic resolution: Asymmetric synthesis of bis-THF alcohol intermediate of darunavir
More, Ganesh V.,Malekar, Pushpa V.,Kalshetti, Rupali G.,Shinde, Mahesh H.,Ramana, Chepuri V.
, (2021/02/16)
The Ru-catalyzed enantio- and diastereoselective dynamic kinetic resolution of α-(benzyloxy/benzoyloxy)acyl-γ-butyrolactones has been examined via transfer hydrogenation. Employing the in situ prepared (R,R)-Ru-FsDPEN catalyst, the transfer hydrogenation of using formic acid/triethylamine at rt gave the corresponding (S)-3-((S)-2-(benzyloxy/benzoyloxy)-1-hydroxyethyl)dihydrofuran-2(3H)-one with good to excellent diastereo- and enantioselectivity. One of the resulting hydrogenation product prepared on gram scales was utilized for the synthesis of (3R,3aS,6aR)-hexahydrofuro[2,3–b]furan-3-ol (1), a key synthetic intermediate of various HIV protease inhibitors such as darunavir with excellent enantio- (95% ee) and diastereoselectivities (dr 95:5).
Stereogenic: Cis -2-substituted- N -acetyl-3-hydroxy-indolines via ruthenium(ii)-catalyzed dynamic kinetic resolution-asymmetric transfer hydrogenation
Luo, Zhonghua,Sun, Guodong,Zhou, Zihong,Liu, Guozhu,Luan, Baolei,Lin, Yicao,Zhang, Lei,Wang, Zhongqing
supporting information, p. 13503 - 13506 (2018/12/12)
Ruthenium(ii)-catalyzed dynamic kinetic resolution-asymmetric transfer hydrogenation of racemic 2-substituted-N-acetyl-3-oxoindolines to cis-2-substituted-N-acetyl-3-hydroxyindolines is reported. Using the homochiral {Ru[TfDPEN](p-cymene)} catalyst with S/C = 400 in a HCO2H/Et3N mixture, up to >99.9% ee and >99:1 dr are obtained with high yields (79-98%). This method provides the first example of preparing enantiomerically pure indolines through asymmetric transfer hydrogenation (ATH).
Highly Enantioselective Synthesis of syn-β-Hydroxy α-Dibenzylamino Esters via DKR Asymmetric Transfer Hydrogenation and Gram-Scale Preparation of Droxidopa
Sun, Guodong,Zhou, Zihong,Luo, Zhonghua,Wang, Hailong,Chen, Lei,Xu, Yongbo,Li, Shun,Jian, Weilin,Zeng, Jiebin,Hu, Benquan,Han, Xiaodong,Lin, Yicao,Wang, Zhongqing
supporting information, p. 4339 - 4342 (2017/08/23)
A highly efficient preparation of enantiomerically pure syn aryl β-hydroxy α-dibenzylamino esters is reported. The outcome was achieved via dynamic kinetic resolution and asymmetric transfer hydrogenation of aryl α-dibenzylamino β-keto esters. The desired products were obtained in high yields (up to 98%) with excellent diastereoselectivity (>20:1 dr) and enantioselectivity (up to >99% ee). Furthermore, this method was applied for the gram-scale preparation of droxidopa.
