92012-22-1Relevant academic research and scientific papers
Efficient Analysis of 2-Acetyl-1-pyrroline in Foods Using a Novel Derivatization Strategy and LC-MS/MS
Jost, Tobias,Heymann, Thomas,Glomb, Marcus A.
, p. 3046 - 3054 (2019/03/11)
2-Acetyl-1-pyrroline (2-AP) is a key odorant in many foods, such as aromatic rice and wheat bread, with a very low odor threshold of 0.05 μg/L in water. The small molecule with a popcornlike, roasty odor is generated biologically or by Strecker degradation within the Maillard-reaction cascades during thermal food processing with methylglyoxal and 1-pyrroline as the main direct precursors. Numerous gas-chromatographic methods for the analysis of 2-AP have been published, but the reactivity of the compound leads to discrimination or degradation during sample workup. We developed a novel derivatization method for 2-AP with o-phenylenediamine followed by HPLC-MS/MS analysis of the resulting stable quinoxaline. The precision (7%), repeatability (14%), recovery (92%), linearity (0.79-500 μg/kg), limit of detection (LOD, 0.26 μg/kg), and limit of quantitation (LOQ, 0.79 μg/kg) were validated for rice matrix and were excellent as compared with those of methods published before. With the novel method, 2-AP levels in typical foods like aromatic rice (131 μg/kg), wheat bread (18 μg/kg), brown bread (18 μg/kg), rye bread (18 μg/kg), and popcorn (38 μg/kg) were determined.
Palladium-catalyzed asymmetric allylic alkylation of acyclic ketones for synthesis of 2,2-disubsituted pyrrolidine derivatives
Lian, Wen-Fang,Wang, Cui-Cui,Kang, Huai-Ping,Li, Hai-Ling,Feng, Juan,Liu, Shouxin,Zhang, Zhi-Wei
supporting information, p. 1399 - 1402 (2017/03/17)
Palladium-catalyzed asymmetric allylic alkylation of acyclic ketones represents a significant challenge in organic synthesis. We report herein that the synthesis of chiral 2,2-disubsituted pyrrolidines from acyclic ketones has been accomplished by using catalytic asymmetric method in the presence of Pd(dba)2 and (R)-binap ligand. Theses reactions occur between allyl methyl carbonate and unstabilized acyclic lithium enolates to provide the products in moderate to good enantioselectivity (up to 81% ee).
New short and general synthesis of three key Maillard flavour compounds: 2-Acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine
Deblander, Jurgen,Van Aeken, Sam,Adams, An,De Kimpe, Norbert,Abbaspour Tehrani, Kourosch
, p. 327 - 331 (2014/08/18)
A new general synthetic route towards three key Maillard flavour compounds, namely 2-acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine, was developed. The key step in the process is the methylenation reaction of azaheterocyclic carboxylic esters by means of dimethyltitanocene, giving rise to intermediate vinyl ethers which can be considered as excellent and stable precursors for the title compounds, as a simple acidic treatment of these precursors suffices to release the characteristic Maillard flavours.
New short and general synthesis of three key Maillard flavour compounds: 2-Acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine
Deblander, Jurgen,Van Aeken, Sam,Adams, An,De Kimpe, Norbert,Abbaspour Tehrani, Kourosch
, p. 327 - 331 (2015/01/30)
A new general synthetic route towards three key Maillard flavour compounds, namely 2-acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine, was developed. The key step in the process is the methylenation reaction of azaheterocyclic carboxylic esters by means of dimethyltitanocene, giving rise to intermediate vinyl ethers which can be considered as excellent and stable precursors for the title compounds, as a simple acidic treatment of these precursors suffices to release the characteristic Maillard flavours.
Arylation of α-chiral ketones by palladium-catalyzed cross-coupling reactions of tosylhydrazones with aryl halides
Barluenga, Jose,Escribano, Maria,Aznar, Fernando,Valde, Carlos
supporting information; experimental part, p. 6856 - 6859 (2010/12/19)
(Figure Presented) Papa was a rollin' ketone: Arylation of ketones with preservation of the chirality in configurationally unstable α-chiral ketones has been achieved by the palladium-catalyzed cross-coupling reaction between tosylhydrazones and aryl halides (see scheme; Boc=tert-butoxycarbonyl, Ts=4-toluenesulfonyl). The regioselectivity in the β-hydride elimination step is key for the retention of configuration.
Microwave-assisted synthesis of novel (5-nitropyridin-2-yl)alkyl and (5-nitropyridin-3-yl)alkyl carbamates
Henry, Christophe,Haupt, Andreas,Turner, Sean C.
supporting information; experimental part, p. 1932 - 1938 (2009/08/07)
A straightforward approach to novel (5-nitropyridin-2-yl)alkyl and (5-nitropyridin-3-yl)alkyl carbamate building blocks is presented in this study. Their construction is achieved by condensation of N-carbamate a- and β-amino carbonyl derivatives with l-methyl-3,5-dinitro-2-pyridone 1 under microwave irradiation. Judiciously chosen modifications in the nature of the parent carbonyl starting material has influenced the regiochemical outcome of the reaction and allowed an efficient access to novel nitrogen-containing scaffolds. Compounds sharing morphological similarities have been gathered in three libraries differing from each other in a single structural parameter.
Catalytic Hydrogenation of Pyrroles at Atmospheric Pressure
Kaiser, Hans-Peter,Muchowski, Joseph M.
, p. 4203 - 4209 (2007/10/02)
N-(tert-Butoxycarbonyl)pyrroles are catalytically hydrogenated to the corresponding pyrrolidines, over 5percent platinum on carbon catalyst, at room temperature and atmospheric pressure.Under these conditions O-benzyl groups are retained and 2,5-disubstit
