ChemInform Abstract: Asymmetric Construction of Quaternary Stereocenters by Magnesium Catalyzed Direct Amination of β-Ketoesters Using in situ Generated Nitrosocarbonyl Compounds as Nitrogen Sources.

ChemInform ◽  
2015 ◽  
Vol 46 (8) ◽  
pp. no-no
Author(s):  
Biplab Maji ◽  
Mahiuddin Baidya ◽  
Hisashi Yamamoto
2014 ◽  
Vol 5 (10) ◽  
pp. 3941-3945 ◽  
Author(s):  
Biplab Maji ◽  
Mahiuddin Baidya ◽  
Hisashi Yamamoto

An oxophilic magnesium salt in combination with a chiral N,N′-dioxide ligand switches the chemoselectivity of an ambident nitrosocarbonyl species to nitrogen for the highly enantioselective α-amination of β-ketoesters.


ChemInform ◽  
2011 ◽  
Vol 42 (28) ◽  
pp. no-no
Author(s):  
Jian Wang ◽  
Ji-Ting Hou ◽  
Jun Wen ◽  
Ji Zhang ◽  
Xiao-Qi Yu

2020 ◽  
Vol 56 (20) ◽  
pp. 3031-3034 ◽  
Author(s):  
Kyu Terashima ◽  
Tomoko Kawasaki-Takasuka ◽  
Tomohiro Agou ◽  
Toshio Kubota ◽  
Takashi Yamazaki

Development of a new synthetic method for the construction of quaternary centers with a CF3 group was realized by way of 1,6-addition of various nucleophiles to highly reactive δ-trifluoromethylated p-quinone methides generated in situ.


Author(s):  
Xiang-Jin Zhang ◽  
Jian-Kang Cao ◽  
Jun-Jie Ren ◽  
Lin Hong ◽  
Ru-Jin Liang ◽  
...  

A high-efficiency strategy for the synthesis of furoxans and 1,2,4-oxadiazoles has been developed, utilizing tert-butyl nitrite (TBN) as nitrogen sources. Azaarene nitrile oxides as activated intermediates were generated in-situ via...


2011 ◽  
Vol 47 (12) ◽  
pp. 3652 ◽  
Author(s):  
Jian Wang ◽  
Ji-Ting Hou ◽  
Jun Wen ◽  
Ji Zhang ◽  
Xiao-Qi Yu

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 694 ◽  
Author(s):  
Patthranit Narueworanon ◽  
Lakkana Laopaiboon ◽  
Niphaphat Phukoetphim ◽  
Pattana Laopaiboon

Low-cost nitrogen sources, i.e., dried spent yeast (DSY), rice bran (RB), soybean meal (SM), urea and ammonium sulfate were used for batch butanol fermentation from sugarcane molasses by Clostridium beijerinckii TISTR 1461 under anaerobic conditions. Among these five low-cost nitrogen sources, DSY at 1.53 g/L (nitrogen content equal to that of 1 g/L of yeast extract) was found to be the most suitable. At an initial sugar level of 60 g/L, the maximum butanol concentration (PB), productivity (QB) and yield (YB/S) were 11.19 g/L, 0.23 g/L·h and 0.31 g/g, respectively. To improve the butanol production, the concentrations of initial sugar, DSY and calcium carbonate were varied using response surface methodology (RSM) based on Box–Behnken design. It was found that the optimal conditions for high butanol production were initial sugar, 50 g/L; DSY, 6 g/L and calcium carbonate, 6.6 g/L. Under these conditions, the highest experimental PB, QB and YB/S values were 11.38 g/L, 0.32 g/L·h and 0.40 g/g, respectively with 50% sugar consumption (SC). The PB with neither DSY nor CaCO3 was only 8.53 g/L. When an in situ gas stripping system was connected to the fermenter to remove butanol produced during the fermentation, the PB was increased to 15.33 g/L, whereas the YB/S (0.39 g/g) was not changed. However, the QB was decreased to 0.21 g/L·h with 75% SC.


2011 ◽  
Vol 31 (12) ◽  
pp. 1390-1400 ◽  
Author(s):  
R. El Zein ◽  
N. Breda ◽  
D. Gerant ◽  
B. Zeller ◽  
P. Maillard

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