122-69-0Relevant academic research and scientific papers
Visible Light-Mediated Synthesis of Enantiopure γ-Cyclobutane Amino and 3-(Aminomethyl)-5-phenylpentanoic Acids
Kerres, Sabine,Plut, Eva,Malcherek, Simon,Rehbein, Julia,Reiser, Oliver
, (2019/02/07)
A visible light-mediated [2+2] photocycloaddition of amide-linked dienes using [Ir(dtb-bpy)(dF(CF3)ppy)2]PF6 as triplet sensitizer was applied to generate a variety of N-tert-butyl, N-benzyl- and N-tert-butoxycarbonyl-protected 3-azabicyclo[3.2.0]heptan-2-ones in good yields and with good diastereoselectivity. Density functional theory calculations shed light on the conformational prerequisites for the [2+2] photocycloaddition. The bicyclic key structures could be readily transformed into γ-cyclobutane amino acids. For the obtained racemic 3-phenyl-2-aminocyclobutane-1-carboxylic acid the resolution with chiral oxazolidin-2-one is demonstrated to allow access to both enantiomers. Alternatively, a chiral auxiliary approach led as well to the enantiomerically pure target compound. Finally, the synthesis of either enantiomer of 3-(aminomethyl)-5-phenylpentanoic acid, the racemate being described as an anticonvulsant, is described.
Visible Light-Mediated Synthesis of Enantiopure g-Cyclobutane Amino and 3-(Aminomethyl)-5-phenylpentanoic Acids
Kerres, Sabine,Plut, Eva,Malcherek, Simon,Rehbein, Julia,Reiser, Oliver
, p. 1400 - 1407 (2019/10/28)
A visible light-mediated [2+2] photocycloaddition of amide-linked dienes using [Ir(dtb-bpy)(dF(CF3)ppy)2]PF6 as triplet sensitizer was applied to generate a variety of N-tert-butyl, N-benzyl- and N-tert-butoxycarbonyl-protected 3-aza-bicyclo[3.2.0]heptan-2-ones in good yields and with good diastereoselectivity. Density functional theory calculations shed light on the conformational prerequisites for the [2+2] photocycloaddition. The bicyclic key structures could be readily transformed into g-cyclobutane amino acids. For the obtained racemic 3-phenyl-2-aminocyclobu-tane-1-carboxylic acid the resolution with chiral oxazolidin-2-one is demonstrated to allow access to both enantiomers. Alternatively, a chiral auxiliary approach led as well to the enantiomerically pure target compound. Finally, the synthesis of either enantiomer of 3-(aminomethyl)-5-phenylpentanoic acid, the racemate being described as an anticonvulsant is described.
Aerobic Acyloxylation of Allylic C?H Bonds Initiated by a Pd0 Precatalyst with 4,5-Diazafluoren-9-one as an Ancillary Ligand
Kozack, Caitlin V.,Sowin, Jennifer A.,Jaworski, Jonathan N.,Iosub, Andrei V.,Stahl, Shannon S.
, p. 3003 - 3007 (2019/06/17)
Palladium-catalyzed allylic C?H oxidation has been widely studied, but most precedents use acetic acid as the coupling partner. In this study, a method compatible with diverse carboxylic acid partners has been developed. Use of a Pd0 precatalyst under aerobic reaction conditions leads to oxidation of Pd0 by O2 in the presence of the desired carboxylic acid to generate a PdII dicarboxylate that promotes acyloxylation of the allylic C?H bond. Good-to-excellent yields are obtained with a roughly 1:1 ratio of the alkene and carboxylic acid reagents. Optimized reaction conditions employ 4,5-diazafluoren-9-one (DAF) as a ligand, in combination with a quinone/iron phthalocyanine cocatalyst system to support aerobic catalytic turnover.
Preparation method of cinnamyl cinnamate
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Paragraph 0054-0061; 0064; 0072; 0080, (2018/04/26)
The invention relates to a preparation method of cinnamyl cinnamate. In an oil bath, methyl cinanmate, cinnamyl alcohol and potassium carbonate are mixed and heated under stirring, and low boiling substances are distilled off while reacting, heating is stopped to cool, water and ethyl acetate are added for washing until the water phase is neutral, and the oil phase is subjected to reduced pressuredistillation after being heated to recover ethyl acetate so as to obtain cinnamyl cinnamate crude products, and the cinnamyl cinnamate crude products are recrystallized from ethanol to obtain white solid cinnamyl cinnamate. The preparation method has the advantages of simple process, short cycle, high yield, simple post-treatment, green environmental protection and the like. The cinnamyl cinnamate prepared according to the method has the advantages of pure aroma, good color, high purity and the like.
Rethinking the Claisen–Tishchenko Reaction
Morris, Stacey A.,Gusev, Dmitry G.
supporting information, p. 6228 - 6231 (2017/05/19)
Pincer-type complexes [OsH2(CO){PyCH2NHCH2CH2NHPtBu2}] and [OsH2(CO){HN(CH2CH2PiPr2)2}] catalyze the disproportionation reaction of aldehydes via an outer-sphere bifunctional mechanism achieving turnover frequencies up to 14 000 h?1. The N?H group of the catalysts is a key player in this process, elucidated with the help of DFT calculations.
Modified Yamaguchi reagent: Convenient and efficient esterification
Okuno, Yoshinori,Isomura, Shigeki,Nishibayashi, Akihiro,Hosoi, Aiko,Fukuyama, Kei,Ohba, Masashi,Takeda, Kazuyoshi
supporting information, p. 2854 - 2860 (2014/10/15)
A convenient and efficient esterification method that used a modified Yamaguchi reagent (2,4,6-trichlorobenzoyl chloride-4-dimethylaminopyridine) and avoided use not only of intractable acid chloride but also of acid anhydrides was proposed. The reaction mechanism was described by Fourier transform infrared spectroscopy and supported by a density functional theory calculation.
NHC-catalyzed one-pot oxidation and oxidative esterification of allylic alcohols using TEMPO: The effect of alcohol additives
Kang, Ye-Won,Jang, Hye-Young
, p. 44486 - 44490 (2015/01/09)
A combination of N-heterocyclic carbene (NHC) catalysts and 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) was proposed for the synthesis of allylic esters from allylic alcohols. The yield of one-pot conversion of allylic alcohols to esters increased when hexafluoroisopropanol (HFIP) was used. The effect of HFIP in this tandem reaction was investigated by monitoring the reaction using gas chromatographic analysis. Control experiments using oxoammonium showed that the oxidative esterification occurred via a single-electron transfer mechanism.
N-heterocyclic carbene catalysed oxidative coupling of aldehydes with alcohols/thiols and one-pot oxidation/esterification of allylic alcohols
Ji, Miran,Wang, Xi,Lim, Yu Na,Kang, Ye-Won,Jang, Hye-Young
supporting information, p. 7881 - 7885 (2014/01/06)
A versatile carbene-catalysed oxidation protocol involving N-heterocyclic carbene catalysts and 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) is described for the synthesis of esters, cinnamic acids, and thioesters. A wide range of esters, thioesters, and cinnamic acids were obtained by metal-free coupling of aldehydes with aliphatic, allylic and aromatic alcohols, benzyl mercaptan, and water. In addition to the oxidative coupling of aldehydes with nucleophiles, dehydrogenation of saturated aldehydes and oxidation of allylic alcohols were found under our oxidative coupling conditions. Unlike other TEMPO-mediated oxidative esterification reactions, this reaction does not proceed through a TEMPO ester intermediate to form esters and thioesters. N-Heterocyclic carbene complexes catalyse various oxidative coupling reactions in the presence of TEMPO. A variety of α,β-unsaturated and saturated esters, and aromatic esters and thioesters were synthesised. Copyright
Pd(II)-catalyzed direct olefination of arenes with allylic esters and ethers
Shang, Xiaojie,Xiong, Yun,Zhang, Yuexia,Zhang, Lei,Liu, Zhongquan
supporting information; experimental part, p. 259 - 262 (2012/03/08)
A convenient Pd(II)-catalyzed direct olefination of unactivated arenes with allylic esters and ethers via C-H activation was demonstrated. Under the typical conditions, various aryl-substituted allylic esters and ethers can be prepared. Georg Thieme Verlag Stuttgart - New York.
Palladium-catalyzed oxidative diarylating carbocyclization of enynes
Jiang, Min,Jiang, Tuo,B?ckvall, Jan-E.
experimental part, p. 3538 - 3541 (2012/08/28)
A mild and efficient palladium-catalyzed oxidative diarylating carbocyclization of enynes is described. The reaction tolerates a range of functionalized arylboronic acids to give diarylated products in good yields. Control experiments suggest that the reaction starts with an arylpalladation of the alkyne, followed by carbocyclization, transmetalation, and reductive elimination to afford the diarylated product.
