13305-09-4Relevant articles and documents
187. Primary and Secondary Isotope Effects on Proton Transfers to Diazocarbonyl Compounds
McGarrity, John F.
, p. 1767 - 1778 (1980)
The primary solvent isotope effects on the ASE-2 type hydrolyses of α-diazocarbonyl compounds p-XC6H4CN2CO2CH3 (X=NO2, H, OCH3 and C6H5CN2CON(CH3)2) are found to be identical despite large differences in their overall hydrolysis rates.The secondary solvent isotope effects diminish considerably with diminishing substrate reactivity, and for two substrates they are smaller than those normally anticipated for a simple proton transfer from the lyonium species.An analysis is presented of these and other abnormal secondary isotope effects found elsewhere, involving consideration of the solvation of the reaction complex.
By 2-hydroxy-c b cyanogen synthesis method of a-hydroxy carboxylic acid ester
-
Paragraph 0029-0031, (2016/11/09)
The invention relates to synthesis of alpha-hydroxy carboxylic ester with 2-hydroxy propylene cyanide and corresponding aldehyde or ketone. The existing common alpha-hydroxy carboxylic ester generally needs superior cyan such as trimethylsilyl cyanide, and then hydrolysis is carried out on the cyan, so that the reaction operation is relatively complicated, and post treatment is a trouble. According to the method, 2-hydroxy propylene cyanide and corresponding aldehyde or ketone are mixed directly, 4-dimethylamino-pyridne of the catalysis amount is added, alcohol compound is taken as the solvent, and the product can be obtained by stirring for 10-120 minutes. The method for synthesizing the alpha-hydroxy carboxylic ester is safe and has high efficiency.
Chemoselective esterification of α-hydroxyacids catalyzed by salicylaldehyde through induced intramolecularity
Weng, Shiue-Shien,Li, Hsin-Chun,Yang, Teng-Mao
, p. 1976 - 1986 (2013/03/13)
A new, direct and chemoselective esterification of α-hydroxyacids was developed using a reversible covalent-binding strategy. By taking advantage of acetal chemistry, simple aldehydes can be used to efficiently catalyze the esterification of α-hydroxy carboxylic acids in the presence of β-hydroxyacid moieties or other carboxylic acids in amounts equal to or in excess of the alcohols. A diverse array of α-aryl, α-alkyl, α-heteroaryl, and functionalized α-hydroxyacids were smoothly esterified with 1° and 2° alcohols catalyzed by 10 mol% inexpensive and commercially available salicylaldehyde, furnishing the resultant esterification products in 83-95% yields after a simple basic aqueous workup to remove the unreacted hydroxyacids. In addition, the salicylaldehyde can be recovered through vacuum distillation or silica gel purification, thereby meeting the standards of green chemistry. A mechanistic study proved that the formation of covalent adduct III during our proposed catalytic cycle (Scheme 1A) is responsible for the real catalysis.
