The ortho-substituent on 2,4-bis(trifluoromethyl)phenylboronic acid catalyzed dehydrative condensation between carboxylic acids and amines

2018 ◽  
Vol 54 (43) ◽  
pp. 5410-5413 ◽  
Author(s):  
Ke Wang ◽  
Yanhui Lu ◽  
Kazuaki Ishihara

The ortho-substituent of boronic acid plays a key role in preventing the coordination of amines to the boron atom.

2018 ◽  
Vol 140 (10) ◽  
pp. 3644-3651 ◽  
Author(s):  
Masamichi Tanaka ◽  
Akira Nakagawa ◽  
Nobuya Nishi ◽  
Kiyoko Iijima ◽  
Ryuichi Sawa ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1854 ◽  
Author(s):  
Kentaro Yoshida ◽  
Akane Yamaguchi ◽  
Hiroki Midorikawa ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
...  

Phenylboronic acid-bearing polyamidoamine dendrimer (PBA-PAMAM)/poly(vinyl alcohol) (PVA) multilayer films were prepared through the layer-by-layer (LbL) deposition of PBA-PAMAM solution and PVA solution. PBA-PAMAM/PVA films were constructed successfully through the formation of boronate ester bonds between the boronic acid moiety in PBA and 1,3-diol units in PVA. When the (PBA-PAMAM/PVA)5 films were immersed in rose bengal (RB) solution, RB was adsorbed onto the LbL films. The amount of RB adsorbed was higher in the LbL films immersed in acidic solution than in basic solution. The release of RB from the LbL films was also promoted in the basic solution, while it was suppressed in the acidic solution. The boronic acid ester is oxidized to phenol by hydrogen peroxide (H2O2) and the carbon-boron bond is cleaved, so that the (PBA-PAMAM/PVA)5 films can be decomposed by immersion in H2O2 solution. Therefore, when RB-adsorbed (PBA-PAMAM/PVA)5 films were immersed in H2O2 solution, the release of RB was moderately promoted when the solution was weakly acidic.


2011 ◽  
Vol 52 (19) ◽  
pp. 2465-2467 ◽  
Author(s):  
Rogelio P. Frutos ◽  
Thomas Tampone ◽  
Jason A. Mulder ◽  
Yibo Xu ◽  
Diana Reeves ◽  
...  
Keyword(s):  

1971 ◽  
Vol 49 (17) ◽  
pp. 2797-2802 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski

The sulfuric acid catalyzed acylation of 2-methyl-5-nitroisocarbostyril with carboxylic acid anhydrides gave the corresponding 4-acylated derivatives 3, which underwent reductive cyclization to 2-substituted derivatives of 4-methyl-1,3,4,5-tetrahydropyrrolo[4.3.2.de]isoquinolin-5-one (4). Alkaline hydrolysis of the six-membered lactam in 4 was accompanied by a retro-Mannich reaction to produce 2-substituted indole-4-carboxylic acids in about 40 % overall yield from 3.


Sign in / Sign up

Export Citation Format

Share Document