- Unlocking Amides through Selective C–N Bond Cleavage: Allyl Bromide-Mediated Divergent Synthesis of Nitrogen-Containing Functional Groups
-
We report a new set of reactions based on the unlocking of amides through simple treatment with allyl bromide, creating a common platform for accessing a diverse range of nitrogen-containing functional groups such as primary amides, sulfonamides, primary amines, N-acyl compounds (esters, thioesters, amides), and N-sulfonyl esters. The method has potential industrial applicability, as demonstrated through gram-scale syntheses in batch and in a continuous flow system.
- Govindan, Karthick,Chen, Nian-Qi,Chuang, Yu-Wei,Lin, Wei-Yu
-
supporting information
p. 9419 - 9424
(2021/11/30)
-
- Radical-Mediated Strategies for the Functionalization of Alkenes with Diazo Compounds
-
One of the most common reactions of diazo compounds with alkenes is cyclopropanation, which occurs through metal carbene or free carbene intermediates. Alternative functionalization of alkenes with diazo compounds is limited, and a methodology for the addition of the elements of Z-CHR2 (with Z = H or heteroatom, and CHR2 originates from N2 CR2) across a carbon-carbon double bond has not been reported. Here we report a novel reaction of diazo compounds utilizing a radical-mediated addition strategy to achieve difunctionalization of diverse alkenes. Diazo compounds are transformed to carbon radicals with a photocatalyst or an iron catalyst through PCET processes. The carbon radical selectively adds to diverse alkenes, delivering new carbon radical species, and then forms products through hydroalkylation by thiol-assisted hydrogen atom transfer (HAT), or forms azidoalkylation products through an iron catalytic cycle. These two processes are highly complementary, proceed under mild reaction conditions, and show high functional group tolerance. Furthermore, both transformations are successfully performed on a gram-scale, and diverse γ-amino esters, γ-amino alcohols, and complex spirolactams are easily prepared with commercially available reagents. Mechanistic studies reveal the plausible pathways that link the two processes and explain the unique advantages of each.
- Su, Yong-Liang,Liu, Geng-Xin,Liu, Jun-Wen,Tram, Linh,Qiu, Huang,Doyle, Michael P.
-
supporting information
p. 13846 - 13855
(2020/09/21)
-
- Preparation method of substituted butyrate derivatives
-
The invention discloses a preparation method of substituted butyrate derivatives. The method specifically comprises the following steps: by taking compounds shown in a formula 1, a formula 2 and a formula 3 as raw materials, carrying out an illumination reaction process in the presence of a photocatalyst and a hydrogen transfer catalyst to obtain a target compound shown in a formula I through one-step reaction. The invention discloses a free radical-mediated olefin bifunctional reaction without a cyclopropanation intermediate. The reaction can realize a product which can be obtained through cyclopropanation and cyclopropane ring opening processes traditionally in one step. Meanwhile, the preparation method of the compound is simple, uses cheap and easily available compounds as raw materials, and has the beneficial effects of one-step synthesis, mild reaction conditions, fast reaction, low cost, less generated waste, simple and safe operation, high atom economy, high selectivity, extremely wide substrate applicability, high yield and the like.
- -
-
Paragraph 0129-0132
(2020/07/15)
-
- Simultaneous monitoring of the bioconversion from lysine to glutaric acid by ethyl chloroformate derivatization and gas chromatography-mass spectrometry
-
Glutaric acid is a precursor of a plasticizer that can be used for the production of polyester amides, ester plasticizer, corrosion inhibitor, and others. Glutaric acid can be produced either via bioconversion or chemical synthesis, and some metabolites and intermediates are produced during the reaction. To ensure reaction efficiency, the substrates, intermediates, and products, especially in the bioconversion system, should be closely monitored. Until now, high performance liquid chromatography (HPLC) has generally been used to analyze the glutaric acid-related metabolites, although it demands separate time-consuming derivatization and non-derivatization analyses. To substitute for this unreasonable analytical method, we applied herein a gas chromatography - mass spectrometry (GC-MS) method with ethyl chloroformate (ECF) derivatization to simultaneously monitor the major metabolites. We determined the suitability of GC-MS analysis using defined concentrations of six metabolites (L-lysine, cadaverine, 5-aminovaleric acid, 2-oxoglutaric acid, glutamate, and glutaric acid) and their mass chromatograms, regression equations, regression coefficient values (R2), dynamic ranges (mM), and retention times (RT). This method successfully monitored the production process in complex fermentation broth.
- Bhatia, Shashi Kant,Choi, Tae-Rim,Choi, Yong-Keun,Gurav, Ranjit,Han, Yeong-Hoon,Kim, Hyun-Joong,Kim, Wooseong,Park, Kyungmoon,Park, See-Hyoung,Park, Ye-Lim,Song, Hun-Suk,Yang, Yung-Hun
-
-
- PROCESS FOR DOUBLE CARBONYLATION OF ALLYL ALCOHOLS TO CORRESPONDING DIESTERS
-
The invention relates to a process for doubly carbonylating allyl alcohols to the corresponding diesters, wherein a linear or branched allyl alcohol is reacted with a linear or branched alkanol (alcohol) with supply of CO and in the presence of a catalytic system composed of a palladium complex and at least one organic phosphorus ligand and in the presence of a hydrogen halide selected from HCl, HBr and HI.
- -
-
Paragraph 0064; 0067; 0068
(2017/07/14)
-
- PROCESS FOR DOUBLE CARBONYLATION OF ALLYL ETHERS TO CORRESPONDING DIESTERS
-
The invention relates to a process for doubly carbonylating allyl ethers to the corresponding diesters, wherein a linear or branched allyl ether is reacted with a linear or branched alkanol (alcohol) with supply of CO and in the presence of a catalytic system composed of a palladium complex and at least one organic phosphorus ligand and in the presence of a hydrogen halide selected from HCl, HBr and HI.
- -
-
Paragraph 0095; 0097
(2017/07/14)
-
- The synthesis of di-carboxylate esters using continuous flow vortex fluidics
-
A vortex fluidic device (VFD) is effective in mediating the synthesis of di-esters at room temperature. Processing under ambient conditions allows for a simple and efficient synthesis, whilst operating under continuous flow addresses scalability. The rotational speed of the sample tube and the flow rate were critical variables during reaction optimization, and this relates to the behaviour of the fluid flow at a molecular level. Whilst at specific rotational speeds the tube imparts a vibrational response into the fluid flow, the flow rate dictates residence time and the ability to maintain high levels of shear stress. The combination of mechanically induced vibrations, rapid micromixing, high levels of shear stress and water evaporation results in yields up to 90% for 3.25 minutes or less residence time. These results are key for devising greener and more efficient processes both mediated by the VFD and other continuous flow platforms.
- Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
-
p. 2193 - 2200
(2016/04/19)
-
- METHOD FOR CONTINUOUSLY PREPARING CARBOXYLIC ACID ESTER
-
A method for continuously preparing a carboxylic acid ester is disclosed. In the method of the present invention, a vertical reactor is filled with a solid catalyst, a carboxylic acid and an alcohol are introduced into a lower part of the vertical reactor, esterification is performed to form an esterized mixture, the esterized mixture is output from an upper part of the vertical reactor, and distillation is performed to isolate the carboxylic acid ester. The method of the present invention is simple, easily controlled and environmental friendly, and has significantly high conversion rate and selectivity.
- -
-
Paragraph 0027; 0029; 0034
(2013/11/19)
-
- Vapor pressures and enthalpies of vaporization of a series of the symmetric linear n -alkyl esters of dicarboxylic acids
-
Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkyl esters of dicarboxylic acids R-CO2-(CH 2)n-CO2-R with n = (0 to 4) with R = C 2H5, n-C3H7, and n-C 4H9 have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters with the number n and with Kovat's indices has been found, proving the internal consistency of measured data.
- Lipp, Svetlana V.,Krasnykh, Eugenii L.,Verevkin, Sergey P.
-
body text
p. 800 - 810
(2011/11/05)
-
- CYCLOHEXANE OXIDATION PROCESS BYPRODUCT DERIVATIVES AND METHODS FOR USING THE SAME
-
Disclosed are ester compositions, solvents, cleaning formulations, curing agents, reactive diluent solvents, controlled acid function release agents, polyol monomers, drilling mud and methods of making and using the same. Disclosed compositions include: a) about 10 to 60 weight percent methyl hydroxycaproate; b) about 20 to 80 weight percent dimethyl adipate; c) about 1 to 15 wt % of dimethyl glutarate; d) about 0.1 to 5 wt % of dimethyl succinate; e) about 0.1 to 7 wt % of at least one cyclohexanediol; and f) less than about 20 wt% oligomeric esters.
- -
-
Page/Page column 48-50
(2010/08/05)
-
- Facile and selective procedure for the synthesis of bridged 1,2,4,5-tetraoxanes; Strong Acids As Cosolvents and catalysts for addition of hydrogen peroxide to β-diketones
-
A facile, experimentally simple, and selective method was developed for the synthesis of bridged 1,2,4,5-tetraoxanes based on the reaction of hydrogen peroxide with β-diketones catalyzed by strong acids (H2SO 4, HC1O4, HBF
- Terent'ev, Alexander O.,Borisov, Dmitry A.,Chernyshev, Vladimir V.,Nikishin, Gennady I.
-
supporting information; experimental part
p. 3335 - 3340
(2009/09/08)
-
- Direct oxidative cleavage of α- and β-dicarbonyls and α-hydroxyketones to diesters with KHSO5
-
Presented is a methodology to oxidatively cleave α-hydroxyketones and α- or β-diones using the environmentally benign reagent KHSO 5, prepared easily from Oxone, to diesters in one simple transformation. In addition, we undertook a mechanistic study to provide a plausible mechanistic interpretation. These reactions may prove to be valuable alternatives to other related metal-mediated processes.
- Yan, Jun,Travis, Benjamin R.,Borhan, Babak
-
p. 9299 - 9302
(2007/10/03)
-
- Spiroaziridination of cycloalkylidene esters under high pressure
-
The reaction between primary amines and 2-bromo-2-(cycloalkylidene)acetates in alcohol under high pressure provides the expected spiroaziridines in good yields and diastereomeric excesses. With bulky or aromatic amines, this reaction competes with the migration of the double bond, which, migrating from an exo to an endocyclic position, provides an intermediate allylic α-bromo ester, immediately converted into an α-amino ester. It was also possible to develop a tandem version, applying the same high pressure conditions to a 1,4-bis-cyclohexylidene acetate. The corresponding bisspiroaziridine was obtained in good yield and moderate de. However, this reaction did not succeed with 2-chloro-2-(cyclopropylidene)acetate, which produced only glutaric acid derivatives in low yields.
- Rulev, Alexandre,Maddaluno, Jacques
-
p. 2569 - 2576
(2007/10/03)
-
- Electrochemical deacetylation of 1,3-dicarbonyl compounds
-
Mild deacetylation of 1,3-dicarbonyl compounds was achieved by halonium-ion mediated electrolysis. In this reaction, the supporting electrolyte including sodium halide NaX (X = Cl or Br) was essential since the reaction proceeded through substitution by a halonium ion, generated electrochemically at anode, on active methine carbons followed by base-aitalyzed deacctylation, and was terminated by reductive dehalogenation of the formed α-halo carbonyl compounds at cathode.
- Fujimoto, Kazuo,Maekawa, Hirofumi,Matsubara, Yoshiharu,Nishiguchi, Ikuzo
-
p. 143 - 144
(2007/10/03)
-
- Conformational characteristics of aliphatic diesters derived from fluorinated diacids
-
A comparative study of the polarity and conformational characteristics of diethyl hexafluoroglutarate (DEFG) and its hydrogenated diester counterpart, diethyl glutarate (DEG), is reported. The value at 30°C of the mean-square dipole moment 〈μ2〉 of the latter compound, 5.26 D2, is nearly 2 times larger the value of this quantity for the fluorinated diester, which amounts to 12.1 D2 at the same temperature. Values of the conformational energies associated with the rotational states about the skeletal bonds of the acid residue were calculated by combining molecular mechanics with the critical interpretation of the mean-square dipole moment of these compounds, finding that the rotational populations about the different skeletal bonds are similar in both molecules. The evaluation of 〈μ2〉 as a function of the conformational energies indicates that the experimental results are reproduced assuming that the conformation in which the C=O* group eclipses the Cα-Cβ bond in the CβCαC*(O*)O residue is less stable than the alternative conformation in which the carbonyl group eclipses the Cα-F (or Cα- H) bond. The analysis suggests that the high polarity exhibited by DEFG, in comparison with that of DEG, arises from differences in the orientation and the modulus of the dipoles in both compounds rather than from differences in their conformational characteristics.
- Reis-Nunes, Regina C.,Riande, Evaristo,Chavez, Nelson C.,Guzman, Julio
-
p. 13492 - 13497
(2007/10/03)
-
- Synthesis of an Isotopically Isomeric Mixture of 1,4,6,8-Tetramethyl2>azulene and Its Thermal Reaction with Dimethyl Acetylenedicarboxylate
-
Sodium 2>cyclopentadienide in tetrahydrofuran (THF) has been prepared from the corresponding labelled 2>cyclopentadiene which was synthesized from 13CO2 and (chloromethyl)trimethylsilane (cf.Scheme 10) according to an established procedure.It could be shown that the acetate pyrolysis of cis-cyclopentane-1,2-diyl diacetate (cis-22) at 550 +/- 5 deg under reduced pressure (60 Torr) gives five times as much cyclopentadiene as trans-22.The reaction of sodium 2>cyclopentadienide with 2,4,6-trimethylpyrylium tetrafluoroborate in THF leads to the formation of the statistically expected 2:2:1 mixture of 4,6,8-trimethyl2>-, -2>-, and -2>azulene (20; cf.Scheme 7 and Fig. 1).Formylation and reduction of the 2:2:1 mixture 2>-20 results in the formation of a 1:1:1:1:1 mixture of 1,4,6,8-tetramethyl2>-, -2>-, -2>-, -2>-, and -2>azulene (5; cf.Scheme 8 and Fig. 2).The measured 2J(13C,13C) values of 2>-20 and 2>-5 are listed in Tables 1 and 2.Thermal reaction of the 1:1:1:1:1 mixture 2>-5 with the four-fold amound of dimethyl acetylenedicarboxylate (ADM) at 200 deg in tetralin (cf.Scheme 2) gave 5,6,8,10-tetramethyl-2>heptalene-1,2-dicarboxylate (2>-6a; 22percent), its double-bond-shifted (DBS) isomer 2>-6b (19percent), and the corresponding azulene-1,2-dicarboxylate 7 (18percent).The isotopically isomeric mixture of 2>-6a showed no 1J(13C,13C) at C(5) (cf.Fig. 3).This finding is in agreement with the fact that expected primary tricyclic intermediate 2>-8 exhibits at 200 deg in tetralin only cleavage of the C(1)-C(10) bond and formation of a C(7)-C(10) bond (cf.Schemes 6 and 9), but no cleavage of the C(1)-C(11) bond and formation of a C(7)-C(11)-bond.The limits of detection of the applied method is Y>/= 96percent for the observed process, i.e., 2>-5 + ADM -> 2>-8 -> 2>-9 -> 2>-6a (cf.Scheme 6).
- Fallahpour, Reza-Ali,Hansen, Hans-Juergen
-
p. 1419 - 1436
(2007/10/02)
-
- Mild hydrolysis or alcoholysis of amides. Ti(IV) catalyzed conversion of primary carboxamides to carboxylic acids or esters
-
Reaction of primary amides (e.g., 1a or 6-13) or O-methylhydroxamates (1b and 1c) with a catalytic amount of TiCI4 and one equivalent of aqueous HCI converts these compounds in good yields to carboxylic esters (when an alcohol is used as solvent) or to carboxylic acids (when 9:1 dioxane:H2O is used as solvent). These conversions are chemoselective for primary amides: mono- and dialkyl amides are not affected by the reaction conditions. The hydrolysis conditions described do not compromise the stereochemical integrity of an adjacent chiral center. This is exemplified by the hydrolysis of naproxen amide (34) to naproxen (33) without detectable racemization as determined by chiral HPLC.
- Fisher,Caroon,Stabler,Lundberg,Zaidi,Sorensen,Sparacino,Muchowski
-
p. 142 - 145
(2007/10/02)
-