Aliphatic Acyl Chlorides Research Articles

Ultra-stable fully-aromatic microporous polyamide membrane for molecular sieving of nitrogen over volatile organic compound

Microporous polymer membranes are promising candidates for industrial membrane-based gas separation because of their high separation performance. However, their relatively low stability due to the local rearrangement of polymer chains during usage remains a problem. Hence, we propose the construction of a fully aromatic polymer structure in a microporous polymer membrane to enhance membrane stability. Four triptycene-based microporous polyamides were synthesized via the polymerization of 2,6,14-triaminotriptycene with aromatic acyl chloride and/or aliphatic acyl chlorides. Their properties were characterized and compared by using nuclear magnetic resonance (NMR) and Brunauer–Emmett–Teller analyses. The synthesized polyamides were fabricated into composite membranes by employing a solution process; their stability was evaluated for the molecular sieving of nitrogen over volatile organic compounds such as cyclohexane. Low-field NMR and X-ray photoelectron spectroscopy were used to investigate the differences in the properties of membranes with different structures at different times. The results showed that the fully aromatic polyamide membrane made from 2,6,14-triaminotriptycene and aromatic acyl chloride displayed constant rejection (99 %) and nitrogen permeability (approximately 50 Barrer) for the molecular sieving of nitrogen over cyclohexane during 100-d experiments, indicating good stability. This approach paves the way for the industrialization of microporous polymer membranes from a theoretical perspective.

Synthesis of selenol esters via the reaction of acyl chlorides with diselenides in the presence of Zn dust catalyzed by CoCl2·6H2O

A practical and efficient approach for the synthesis of selenol and thiol esters is described via the reaction of acyl chlorides with diselenides or disulfides in the presence of Zn dust catalyzed by inexpensive CoCl2·6H2O This protocol tolerates a wide range of substrates, including aromatic and aliphatic acyl chlorides, with a variety of sensitive functional groups to afford the respective products in good yields. Furthermore, the method was also extended to use anhydrides as substrates. In addition, the obtained selenol esters could be readily transformed into vinyl selenide ketones by the selenocarbonylation of terminal alkynes catalyzed by a palladium/copper system.

The phosphinoboration of acyl chlorides.

This investigation examines the reactivity of phosphinoboronate esters Ph2PBpin (pin = 1,2-O2C2Me4) and Ph2PBcat (cat = 1,2-O2C6H4), as well as other phosphinoboron species, with various aryl and aliphatic acyl chlorides. These reactions proceed smoothly to give acyl phosphines of the type RC(O)PR'2 along with loss of a boron-chloride compound. In some cases, a second equivalent of the phosphinoboron species can add to the C[double bond, length as m-dash]O double bond at elevated temperatures to give the corresponding diphosphines RC(OBR''2)(PR'2)2. These ambiphilic diphosphines behave like substituted (1,1-bis(diphenylphosphino)methane) derivatives in a reaction of PhC(OBpin)(PPh2)2 (2a) with (η5-C9H7)Rh(η2-coe)2 (coe = cis-cyclooctene) affording the indenyl rhodium complex (η5-C9H7)Rh(PhC(OBpin)(PPh2)2) (3a) where the phosphines are bound to the metal centre in a κ2-P,P bidentate manner.

Preparation and Characterization of Acylcaramel.

Caramel is a widely used water-soluble food pigment. The acylation of caramel was conducted by aliphatic acyl chlorides with different chain lengths. Acetyl, butyryl, octyl, lauryl, palmityl, and stearyl caramels were prepared with the ratio of acyl chloride/caramel of 6. The formation of acylated caramel was confirmed by Fourier transform infrared spectra, and the acyl mass fraction in acylcaramel was determined by potentiometric titration. Thermal analysis showed that the weight loss of acylated caramel was higher than that of raw caramel. The scanning electron microscopy analysis showed that the morphology of acylated caramel was significantly different from that of raw material. The acyl mass fraction of acylated caramel increased with the increase of acyl chain lengths. Meanwhile, the lipo-hydro partition coefficient, the solubility in corn oil, and color, red, and yellow indexes increased with the increase of the mass fraction of acyl in acylcaramel. It was found that stearyl caramel has the highest lipid solubility of 5.73 mg/mL in corn oil; however, the color, red, and yellow indexes of palmityl caramel reached 25 818.60, 1.149, and 1.757, respectively. This study provides a method to improve the solubility of caramel in lipid phase and expand the application range of caramel.

Synthesis and catalytic reactivity in Friedel–Crafts acylations of monobridged bis(cyclopentadienyl)molybdenum(I) carbonyl complexes

When the monobridged biscyclopentadienes (C5H5)R(C5H5) [R = C(CH3)2 (1), Si(CH3)2 (2), C(CH2)5 (3)] reacted with Mo(CO)6 in refluxing xylene, the corresponding complexes [(η5-C5H4)2R][Mo(CO)3]2 [R = C(CH3)2 (4), Si(CH3)2 (5), C(CH2)5 (6)] were obtained. These complexes were separated by chromatography and characterized by elemental analysis, IR, and 1H NMR spectroscopy. The molecular structures of 4 and 5 were determined by X-ray diffraction analysis. Friedel–Crafts acylation reactions of anisole derivatives with aromatic or aliphatic acyl chlorides catalyzed by complexes 4–6 showed that all of these monobridged bis(cyclopentadienyl)molybdenum carbonyl complexes have catalytic activity.

Atom Efficient Preparation of Zinc Selenates for the Synthesis of Selenol Esters under "On Water" Conditions.

We describe here an atom efficient procedure to prepare selenol esters in good to excellent yields by reacting [(PhSe)2Zn] or [(PhSe)2Zn]TMEDA with acyl chlorides under “on water” conditions. The method is applicable to a series of aromatic and aliphatic acyl chlorides and tolerates the presence of other functionalities in the starting material.

Development and validation of a general derivatization HPLC method for the trace analysis of acyl chlorides in lipophilic drug substances

Acyl chlorides are important acylating agents in the synthesis of active pharmaceutical ingredients. Determining the residual acyl chlorides in drug substances is a challenge due to their high reactivity and the matrix interferences from drug substances and their related impurities. This paper describes a general derivatization HPLC method for the determination of aromatic and aliphatic acyl chlorides in lipophilic drug substances. Since most drug substances have weak absorptions in the visible range (above 380nm), the nitro-substituted anilines and nitro-substituted phenylhydrazines were selected as the derivatization reagents due to their weak basicity and red-shift of UV absorption spectra. The maximum wavelength and absorption intensity of nitro-substituted anilines decreased after derivatization with acyl chlorides, whereas the derivatization products of nitro-substituted phenylhydrazines showed the slight increases of maximum wavelength and absorbance intensity. Hence, 2-nitrophenylhydrazine was selected as the suitable derivatization reagent because the derivatives have the maximum UV wavelength absorbance at 395nm, which could largely minimize the matrix interferences. The optimization of the concentration of 2-nitrophenylhydrazine is important for the sensitivity and stability of derivatives. Other reaction conditions including reaction temperature, time and the influence of three competitive solvents (water, methanol and ethanol) on the reaction efficiency were also studied. After derivatization with 100μgmL-1 2-nitrophenylhydrazine at room temperature for 30min, the method was validated for high specificity and sensitivity with the detection limits in the range of 0.01-0.03μgmL-1. The proposed method was applied as a generic method to determine the residual acyl chlorides in lipophilic drug substances.

ChemInform Abstract: N‐Monoacylation of Sulfonimidamides

Abstractusing a 1:1 premixed mixture of (hetero)aromatic and aliphatic acyl chlorides and pyridazine as acylating agent under mild reaction conditions

N-Monoacylation of Sulfonimidamides

N-Monoacylated sulfonimidamides, the aza analogue of N-acylsulfonamides which are a common motif in drug discovery, were exclusively synthesized by using a 1:1-premixed mixture of an acyl chloride and pyridazine as the acylating agent, while diacylation exclusively occurred when N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide (EDC) was used as the coupling agent. The monoacylation is fast, easy to operate, and applicable to both aromatic and aliphatic acyl chlorides to give the corresponding products in moderate or high overall yields. A two-step N,N′-diacylated product exemplifies that the sulfonimidamide moiety provides one more handle than its sulfonamide isostere. This stepwise functionalization approach can be used to fine-tune the desired properties of compounds in medicinal chemistry.

Synthesis of aromatic ketones by Suzuki-Miyaura cross-coupling of acyl chlorides with boronic acids mediated by palladium catalysts deposited over donor-functionalized silica gel

Immobilized palladium catalysts prepared by deposition of palladium(II) acetate over silica gel functionalized with Si(CH2)3NHCH2Y donor groups (Y=SMe (1), NMe2 (2), PPh2 (3)) efficiently mediate cross-coupling of benzoyl chloride with benzeneboronic acid and its derivatives possessing electron-donating substituents. The presence of electron-withdrawing groups at the benzene ring decreases the yield of the coupling product while aliphatic acyl chlorides such as PhCH2CH2COCl and t-BuCOCl provide the coupling products in only poor yields. The course of the coupling reaction is very sensitive to the reaction conditions, the best results being achieved with potassium carbonate sesquihydrate as the base in dry toluene. The catalysts, which serve as the source of active metal, gradually loose their activity due to metal leaching and, mainly, decomposition of the solid support presumably by the action of the strong base present in the reaction system.

Ruthenium-Catalyzed C–H Functionalization of Arylpyrazoles: Regioselective Acylation with Acid Chlorides

A ruthenium-catalyzed C-H acylation of arylpyrazoles with a variety of acyl chlorides is described. The acylation reaction exhibits good regioselectivity and both aromatic and aliphatic acyl chlorides can be effectively coupled to the arylpyrazoles at the ortho-position.

Samarium diiodide-mediated reductive couplings of chiral nitrones with aldehydes/ketones and acyl chlorides

The SmI 2-mediated and H 2O-promoted reductive cross-coupling reactions of the l-tartaric acid derived nitrone (3 S,4 S)- 8 with aldehydes/ketones, and the l-malic acid derived nitrone ( S)- 6 with aliphatic acyl chlorides have been investigated, respectively. (2 R,3 S,4 S)-1,3,4-Trihydroxyprolinol derivatives 9a– f were obtained with high C-2/C-3 trans-selectivities, and 72:28–85:15 diastereoselectivities at the carbinol center from aromatic ketones/aldehydes, while low diastereoselectivities for aliphatic aldehydes. Conditions have been established for the syntheses of (2 R,3 S,4 S)-3,4-dihydroxyprolinol derivatives such as 18, by N–O bond cleavage of the corresponding N-hydroxyprolinol derivatives 9b– f, or more conveniently by a one-pot reductive coupling of nitrone 8 and in situ N–O bond cleavage of the resultant coupling product. The 2-acyl-3-benzyloxy-1-hydroxypyrrolidines 10a– f were formed in 48–82% yields, and in 74:26–78:22 diastereoselectivities. It was revealed that the amount of water required for the reaction is substrate-depending.

Trimethylsilyl-1,3,4-oxadiazoles—new useful synthons for the synthesis of various 2,5-disubstituted-1,3,4-oxadiazoles

The reactivity of 2-aryl-5-trimethylsilyl-1,3,4-oxadiazoles toward different types of electrophiles was investigated. These silanes readily react with chlorine, bromine, aliphatic acyl chlorides, 2-nitrobenzenesulfenyl chloride, and some reactive isocyanates affording the corresponding substituted 1,3,4-oxadiazoles. The reactions with carbonyl compounds proceed only in the presence of F − anions.

Palladium-phosphinous acid-catalyzed cross-coupling of aliphatic and aromatic acyl chlorides with boronic acids

The cross-coupling of aromatic and aliphatic acyl chlorides with arylboronic acids in the presence of 2.5 mol % of ( t-Bu 2POH) 2PdCl 2 (POPd) provides rapid access to ketones that are obtained in up to 93% yield. This palladium-phosphinous acid-catalyzed reaction is completed within 10 min when microwave irradiation is used, and it overcomes typical drawbacks of Friedel–Crafts acylation procedures such as harsh reaction conditions, untunable regiocontrol, and low substrate scope.

Photophysical Properties of Luminescent Quaternary Lanthanide Molecular Hybrid Systems with Chemical Bonds from the Cooperative Design and Assembly of Structure and Function

Two long chain aliphatic acyl chlorides (dodecanoyl chloride (C(10)H(19)OCl, abbreviated as DC) and stearoyl chloride (C(18)H(35)Ocl, abbreviated as SC)) were modified by means of the amidation reaction with crosslinking molecules (N-aminopropyl-triethoxylsiliane, (APES, H(2)N(CH(2))(3)Si(OC(2)H(5))(3))) and afford two kinds of structural molecular bridge DC (SC)- APES with double reactivity. Subsequently, according to the principle of coordination chemistry, ternary lanthanide (terbium and europium) molecular complex systems with two molecular bridges DC (SC)- APES and 1,10-phenanthroline (phen) of were successfully assembled. Then the modified molecular bridges behave as structural ligands to form the covalent bond Si- O network with matrix precursor (tetraethoxysilane, TEOS) through a sol-gel process (cohydrolysis and copolycondensation process), resulting in a novel quaternary molecular hybrid material (so called as phen-Tb(Eu)-DC(SC)- APES) with strong chemical bonds (N- Tb(Eu)- O coordination bonds and Si- O covalent bonds). And phen behaves as functional ligand to sensitize the luminescence of terbium or europium ions through the effective intramolecular energy transfer process, which gives rise to the characteristic emission of metal ion.

A general and efficient reduction of acyl chlorides to aldehydes by Sm(0)/Bu 3P

A facile and efficient reduction of aromatic and aliphatic acyl chlorides to their corresponding aldehydes in the presence of Sm(0)/Bu 3P has been developed with broad scope. This method prevents over reduction of products, that is, the over-reduction of aldehydes to alcohols.

Study on the Reductive Acylation of Azo Compounds by SmI2/THF in One Pot

Azobenzene compounds without big substituents were conveniently reduced by a system consisting of SmI2/THF and successively reacted smoothly with analogous aliphatic acyl chlorides or acid anhydrides to afford corresponding mono-acyl symmetrical hydrazobenzene under mild and neutral conditions in one pot; while other azo compounds reacted under similar conditions, amides were the terminate products.

One Pot Preparation of Amides from Azo Compounds by Sm/TiCl4

Azo compounds were conveniently reduced by a system consisting of Sm/TiCl4 to produce aniline anions. This anion species reacted smoothly with aliphatic acyl chlorides or acid anhydrides to afford corresponding amides under mild and neutral conditions.

Indium Promoted‐Convenient Method for Acylation of Alcohols with Acyl Chlorides.

tions for the acylation of alcohols with acyl chlorides in the presence of indium. The results are summarized in Table 1. Reaction of 2 (1 equiv) with 1 (1 equiv) in the presence of indium (1 equiv) in CH3CN at room temperature produced the corresponding ester in only 21% yield and the starting acyl chloride and alcohol were recovered. The optimal yield of the ester was attained with 3 equiv of 1 or 2 in the presence of 3 equiv of indium. The solvent effect of acylation of 2 with 1 in the presence of indium was studied. The reaction proceeded efficiently in common organic solvents such as DMF, Et2O, THF or CH2Cl2 whereas non-polar solvents such as n-hexane or benzene gave poor yields of the ester. The reactivity of acyl halides was studied. The results are presented in Table 2. The results show that aromatic acyl chlorides with electron-withdrawing groups including the non-substituted led to higher yield than those with electrondonating groups. The acylation of alcohol with aliphatic acyl chlorides also proceeded smoothly affording high yields of the ester. It is noteworthy that carbon-carbon double bonds remained intact under the present reaction conditions while the reaction performed under basic reaction conditions led to a double bond isomerized product. 6

A Convenient Method for Preparing Aromatic Ketones from Acyl Chlorides and Arylboronic Acids via Suzuki—Miyaura Type Coupling Reaction.

AbstractFor Abstract see ChemInform Abstract in Full Text.