1504-26-3Relevant articles and documents
Synthesis of β-Hydroxy α-Amino Acids through Br?nsted Base-Catalyzed syn-Selective Direct Aldol Reaction of Schiff Bases of Glycine o-Nitroanilide
Vera, Silvia,Vázquez, Ana,Rodriguez, Ricardo,Pozo, Sandra Del,Urruzuno, I?aki,de Cózar, Abel,Mielgo, Antonia,Palomo, Claudio
, p. 7757 - 7772 (2021/06/21)
Here we report the highly enantio- and syn-selective synthesis of β-hydroxy α-amino acids from glycine imine derivatives under Br?nsted base (BB) catalysis. The key of this approach is the use of benzophenone-derived imine of glycine o-nitroanilide as a pronucleophile, where the o-nitroanilide framework provides an efficient hydrogen-bonding platform that accounts for nucleophile reactivity and diastereoselectivity.
N, N -diethylurea-catalyzed amidation between electron-deficient aryl azides and phenylacetaldehydes
Xie, Sheng,Ramstr??m, Olof,Yan, Mingdi
, p. 636 - 639 (2015/03/04)
Urea structures, of which N,N-diethylurea (DEU) proved to be the most efficient, were discovered to catalyze amidation reactions between electron-deficient aryl azides and phenylacetaldehydes. Experimental data support 1,3-dipolar cycloaddition between DEU-activated enols and electrophilic phenyl azides, especially perfluoroaryl azides, followed by rearrangement of the triazoline intermediate. The activation of the aldehyde under near-neutral conditions was of special importance in inhibiting dehydration/aromatization of the triazoline intermediate, thus promoting the rearrangement to form aryl amides.
On the active site for hydrolysis of aryl amides and choline esters by human cholinesterases
Darvesh, Sultan,McDonald, Robert S.,Darvesh, Katherine V.,Mataija, Diane,Mothana, Sam,Cook, Holly,Carneiro, Karina M.,Richard, Nicole,Walsh, Ryan,Martin, Earl
, p. 4586 - 4599 (2007/10/03)
Cholinesterases, in addition to their well-known esterase action, also show an aryl acylamidase (AAA) activity whereby they catalyze the hydrolysis of amides of certain aromatic amines. The biological function of this catalysis is not known. Furthermore, it is not known whether the esterase catalytic site is involved in the AAA activity of cholinesterases. It has been speculated that the AAA activity, especially that of butyrylcholinesterase (BuChE), may be important in the development of the nervous system and in pathological processes such as formation of neuritic plaques in Alzheimer's disease (AD). The substrate generally used to study the AAA activity of cholinesterases is N-(2-nitrophenyl)acetamide. However, use of this substrate requires high concentrations of enzyme and substrate, and prolonged periods of incubation at elevated temperature. As a consequence, difficulties in performing kinetic analysis of AAA activity associated with cholinesterases have hampered understanding this activity. Because of its potential biological importance, we sought to develop a more efficient and specific substrate for use in studying the AAA activity associated with BuChE, and for exploring the catalytic site for this hydrolysis. Here, we describe the structure-activity relationships for hydrolysis of anilides by cholinesterases. These studies led to a substrate, N-(2-nitrophenyl)trifluoroacetamide, that was hydrolyzed several orders of magnitude faster than N-(2-nitrophenyl)acetamide by cholinesterases. Also, larger N-(2-nitrophenyl)alkylamides were found to be more rapidly hydrolyzed by BuChE than N-(2-nitrophenyl)acetamide and, in addition, were more specific for hydrolysis by BuChE. Thus, N-(2-nitrophenyl)alkylamides with six to eight carbon atoms in the acyl group represent suitable specific substrates to investigate further the function of the AAA activity of BuChE. Based on the substrate structure-activity relationships and kinetic studies, the hydrolysis of anilides and esters of choline appears to utilize the same catalytic site in BuChE.
