136125-68-3Relevant articles and documents
Visible-Light-Induced Catalyst-Free Carboxylation of Acylsilanes with Carbon Dioxide
Fan, Zhengning,Yi, Yaping,Chen, Shenhao,Xi, Chanjuan
, p. 2303 - 2307 (2021/04/05)
Intermolecular carbon-carbon bond formation between acylsilanes and carbon dioxide (CO2) was achieved by photoirradiation under catalyst-free conditions. In this reaction, siloxycarbenes generated by photoisomerization of the acylsilanes added to the C═O bond of CO2 to give α-ketocarboxylates, which underwent hydrolysis to afford α-ketocarboxylic derivatives in good yields. Control experiments suggest that the generated siloxycarbene is likely to be from the singlet state (S1) of the acylsilane and the addition to CO2 is not in a concerted manner.
Silyl Cyanopalladate-Catalyzed Friedel-Crafts-Type Cyclization Affording 3-Aryloxindole Derivatives
Ece, Hamdiye,Tange, Yuji,Yurino, Taiga,Ohkuma, Takeshi
, p. 935 - 939 (2021/02/22)
3-Aryloxindole derivatives were synthesized through a Friedel-Crafts-type cyclization. The reaction was catalyzed by a trimethylsilyl tricyanopalladate complex generated in situ from trimethylsilyl cyanide and Pd(OAc) 2. Wide varieties of diethyl phosphates derived from N -arylmandelamides were converted almost quantitatively into oxindoles. When N, N -dibenzylamide was used instead of an anilide substrate, a benzo-fused δ-lactam was obtained. An oxindole product was subjected to substitution reactions to afford 3,3-diaryloxindoles with two different aryl groups.
Tandem Photoredox-Chiral Phosphoric Acid Catalyzed Radical-Radical Cross-Coupling for Enantioselective Synthesis of 3-Hydroxyoxindoles
Zhang, Yang,Ye, Dan,Shen, Lei,Liang, Kangjiang,Xia, Chengfeng
supporting information, p. 7112 - 7117 (2021/09/14)
A photochemical protocol that couples diarylamines and α-ketoesters to afford the chiral 3-hydroxyoxindoles through tandem photoredox and chiral phosphoric acid catalysis is developed. The reaction involves an enantioselective photochemical radical-radical cross-coupling process. The chiral phosphoric acid is discovered to play crucial roles by decreasing the reductive potentials of α-ketoesters and stereocontrolling the downstream asymmetric radical-radical cross-coupling via the formation of pentacoordinate complex.
Carbene-Catalyzed Enantioselective Aromatic N-Nucleophilic Addition of Heteroarenes to Ketones
Liu, Yonggui,Luo, Guoyong,Yang, Xing,Jiang, Shichun,Xue, Wei,Chi, Yonggui Robin,Jin, Zhichao
supporting information, p. 442 - 448 (2019/11/25)
The aromatic nitrogen atoms of heteroarylaldehydes are activated by carbene catalysts to react with ketone electrophiles. Multi-functionalized cyclic N,O-acetal products are afforded in good to excellent yields and optical purities. Our reaction involves the formation of an unprecedented aza-fulvene-type acylazolium intermediate. A broad range of N-heteroaromatic aldehydes and electron-deficient ketone substrates works effectively in this transformation. Several of the chiral N,O-acetal products afforded through this protocol exhibit excellent antibacterial activities against Ralstonia solanacearum (Rs) and are valuable in the development of novel agrichemicals for plant protection.
Cobalt-Catalyzed Transfer Hydrogenation of α-Ketoesters and N-Cyclicsulfonylimides Using H2O as Hydrogen Source
Gao, Yang,Zhang, Xuexin,Laishram, Ronibala Devi,Chen, Jingchao,Li, Kangkui,Zhang, Keyang,Zeng, Guangzhi,Fan, Baomin
supporting information, p. 3991 - 3997 (2019/08/02)
A Co-catalyzed effective transfer hydrogenation of various α-ketoesters and N-cyclicsulfonylimides by safe and environmentally benign H2O as hydrogen source is described. The reaction used easily available and easy to handle zinc metal as a reductant. Interestingly, the catalytic system does not require ligand for reduction of N-cyclicsulfonylimides. (Figure presented.).
Anti-Selective Catalytic Asymmetric Nitroaldol Reaction of α-Keto Esters: Intriguing Solvent Effect, Flow Reaction, and Synthesis of Active Pharmaceutical Ingredients
Karasawa, Tomoya,Oriez, Rapha?l,Kumagai, Naoya,Shibasaki, Masakatsu
supporting information, p. 12290 - 12295 (2018/09/27)
A rare-earth metal/alkali metal bimetallic catalyst proved particularly effective for enantioselectively coupling nitroalkanes and α-keto esters in an anti-selective manner to afford synthetically versatile, densely functionalized, and optically active α-nitro tertiary alcohols. A chiral diamide ligand captured two distinct metal cations, giving rise to a catalytically competent solid-phase heterobimetallic catalyst by simple mixing via self-assembly. The advantage of the solid-phase asymmetric catalyst was realized by successful application to the enantio- and diastereoselective reaction in a continuous-flow platform. The use of closely related solvents in terms of structures and polarity parameters, THF and its methylated congener 2-Me-THF, had an unexpectedly large solvent effect both on the reaction rate and the stereoselectivity. The nitroaldol products share a privileged unit for active pharmaceutical ingredients, as demonstrated by the streamlined enantioselective synthesis of the marketed antifungal agents efinaconazole and albaconazole.
Visible Light Promotes Decyanation Esterification Reaction of β - Ketonitriles with Dioxygen and Alcohols to α-Ketoesters
Xu, Chen,Zhang, Nan-Nan,Li, Xiao-Ji,Ge, Yan-Qin,Diao, Pin-Hui,Guo, Cheng
supporting information, p. 1065 - 1070 (2018/05/01)
A green and mild method has been developed for the conversion of β-ketonitriles into α-ketoesters under catalyst-free conditions. A plausible mechanism is that visible light promotes singlet oxygen generation to form the products through oxidative C-H bond functionalization and C-C σ -bond cleavage.
Enantioselective Iridium-Catalyzed Hydrogenation of α-Keto Amides to α-Hydroxy Amides
Gu, Guoxian,Yang, Tilong,Yu, Ouran,Qian, Hua,Wang, Jiang,Wen, Jialin,Dang, Li,Zhang, Xumu
supporting information, p. 5920 - 5923 (2017/11/10)
A highly enantioselective iridium-catalyzed hydrogenation of α-keto amides to form α-hydroxy amides has been achieved with excellent results (up to >99% conversion and up to >99% ee, TON up to 100?000). As an example, this protocol was applied to the synthesis of (S)-4-(2-amino-1-hydroxyethyl)benzene-1,2-diol, the enantiomer of norepinephrine, which is widely used as an injectable drug for the treatment of critically low blood pressure. Density functional theory (DFT) calculations were also carried out to reveal the reaction mechanism.
Rh-catalyzed asymmetric hydrogenation of racemic aldimines via dynamic kinetic resolution
Fan, Dongyang,Lu, Jian,Liu, Yang,Zhang, Zhenfeng,Liu, Yangang,Zhang, Wanbin
, p. 5541 - 5547 (2016/08/05)
Catalyzed by a rhodium complex of P-stereogenic diphosphine ligand trichickenfootphos (TCFP), asymmetric hydrogenation of racemic aldimines via dynamic kinetic resolution has been realized for the preparation of chiral arylglycines with good yields and enantioselectivities.
Direct asymmetric hydrogenation of α-keto acids by using the highly efficient chiral spiro iridium catalysts
Yan, Pu-Cha,Xie, Jian-Hua,Zhang, Xiang-Dong,Chen, Kang,Li, Yuan-Qiang,Zhou, Qi-Lin,Che, Da-Qing
supporting information, p. 15987 - 15990 (2015/02/19)
A new efficient and highly enantioselective direct asymmetric hydrogenation of α-keto acids employing the Ir/SpiroPAP catalyst under mild reaction conditions has been developed. This method might be feasible for the preparation of a series of chiral α-hydroxy acids on a large scale.
