Enantioselective synthesis of 1,2,3,4-tetrahydroquinoline-4-ols and 2,3-dihydroquinolin-4(1H)-ones via a sequential asymmetric hydroxylation/diastereoselective oxidation process using Rhodococcus equi ZMU-LK19

2017 ◽  
Vol 15 (17) ◽  
pp. 3580-3584 ◽  
Author(s):  
Ke Li ◽  
Juxiang Wang ◽  
Kailin Wu ◽  
Daijun Zheng ◽  
Xiaojian Zhou ◽  
...  
Keyword(s):  
Oxidation Process ◽  
Rhodococcus Equi ◽  
Enantioselective Synthesis ◽  
Cascade Biocatalysis ◽  
Asymmetric Hydroxylation

A cascade biocatalysis system involving asymmetric hydroxylation and diastereoselective oxidation was developed giving the title compounds in good yields.

Asymmetric ring opening of racemic epoxides for enantioselective synthesis of (S)-β-amino alcohols by a cofactor self-sufficient cascade biocatalysis system

2019 ◽  
Vol 9 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Jian-Dong Zhang ◽  
Xiao-Xiao Yang ◽  
Qiao Jia ◽  
Jian-Wei Zhao ◽  
Li-Li Gao ◽  
...  
Keyword(s):  
Ring Opening ◽  
Amino Alcohols ◽  
Enantioselective Synthesis ◽  
System P ◽  
Cascade Biocatalysis ◽  
Asymmetric Ring Opening

Asymmetric ring opening of racemic epoxides to enantiopure β-amino alcohols via a cascade biocatalysis system.

Total Synthesis of Camptothecins: An Update

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1134-1150 ◽  
Author(s):  
Fen-Er Chen ◽  
Lei Chen
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Enantioselective Synthesis ◽  
The Novel ◽  
Asymmetric Dihydroxylation ◽  
New Methods ◽  
Considerable Research ◽  
Catalytic Asymmetric ◽  
Synthetic Approaches ◽  
Asymmetric Hydroxylation

Over the last few decades, considerable research efforts have been directed toward the development of effective chemical syntheses of camptothecin and its analogs. The last comprehensive review of this area was published in 2003 and many effective new methods have since been reported for the stereoselective synthesis of the camptothecin alkaloids. In this account, we have summarized most of the novel synthetic approaches developed for the synthesis of camptothecins during the last decade. We have focused on strategies for the construction of the pentacyclic ring system and the different methods used to install the chiral quaternary center on the E ring of camptothecin.1 Introduction2 Synthesis of Racemic Camptothecins3 Enantioselective Synthesis of Camptothecins3.1 Sharpless Asymmetric Dihydroxylation3.2 Catalytic Asymmetric Cyanosilylation3.3 Auxiliary-Induced Asymmetric Carbonyl Addition3.4 Catalytic Asymmetric Ethylation3.5 Asymmetric Hydroxylation4 Conclusion

Enantioselective synthesis of (+)-citreoviral using asymmetric hydroxylation of tiglate esters

1985 ◽  
Vol 26 (52) ◽  
pp. 6485-6488 ◽  
Author(s):  
Susumi Hatakeyama ◽  
Yumiko Matsui ◽  
Masahiro Suzuki ◽  
Kuniya Sakurai ◽  
Seiichi Takano
Keyword(s):  
Enantioselective Synthesis ◽  
Asymmetric Hydroxylation

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

Structural Imperfections in thin Oxide Films Formed on Some Fe- and Ni-Base Alloys

1970 ◽  
Vol 28 ◽  
pp. 510-511
Author(s):  
L. P. Lemaire ◽  
D. E. Fornwalt ◽  
F. S. Pettit ◽  
B. H. Kear
Keyword(s):  
Oxide Scale ◽  
Oxidation Process ◽  
Short Circuit ◽  
Protective Oxide ◽  
Protective Oxide Scale ◽  
Thin Oxide Films ◽  
Diffusion Paths ◽  
Oxidation Resistant ◽  
Structural Imperfections ◽  
Short Circuit Diffusion

Oxidation resistant alloys depend on the formation of a continuous layer of protective oxide scale during the oxidation process. The initial stages of oxidation of multi-component alloys can be quite complex, since numerous metal oxides can be formed. For oxidation resistance, the composition is adjusted so that selective oxidation occurs of that element whose oxide affords the most protection. Ideally, the protective oxide scale should be i) structurally perfect, so as to avoid short-circuit diffusion paths, and ii) strongly adherent to the alloy substrate, which minimizes spalling in response to thermal cycling. Small concentrations (∼ 0.1%) of certain reactive elements, such as yttrium, markedly improve the adherence of oxide scales in many alloy systems.

Catalytic enantioselective synthesis of indolizino[8,7-b]indole alkaloid derivatives based on the tandem reaction of tertiary enamides

2021 ◽  
Author(s):  
Xin-Ming Xu ◽  
Ming Xie ◽  
Jiazhu Li ◽  
Mei-Xiang Wang
Keyword(s):  
Indole Alkaloid ◽  
Enantioselective Synthesis ◽  
High Yield ◽  
Tandem Reaction ◽  
Indole Derivatives

An exquisite Pybox/Cu(OTf)2-catalyzed asymmetric tandem reaction of tertiary enamides was developed, which enabled the expeditious synthesis of indolizino[8,7-b]indole derivatives in high yield, excellent enantioselectivity and diastereoselectivity.

Sign in / Sign up

Export Citation Format

Share Document