Rhenium complex-catalyzed acylative cleavage of ethers with acyl chlorides

It was found that rhenium complex was an efficient catalyst for the acylative cleavage of C-O bond of ethers with acyl chlorides. When acyclic ethers were allowed to react with acyl chlorides in the presence of a catalytic amount of ReBr(CO)₅, acylative cleavage of C-O bond of acyclic ethers smoothly proceeded to give the corresponding esters in moderate to good yields. Similarly, cyclic ethers were acylative cleaved by acyl chlorides to give the corresponding chloro substituted esters in good yields by the use of Re₂O₇ catalyst.     

Highly efficient synthesis of capsaicin analogues by condensation of vanillylamine and acyl chlorides in a biphase H2O/CHCl3 system

Highly efficient synthesis of capsaicin analogues was developed using condensation of vanillylamine with acyl chlorides in a biphase H₂O/CHCl₃ system under mild conditions. For C4-C18 aliphatic or aromatic acyl chlorides, the yields were up to 93-96% with high purity after a simple work-up procedure, and only 1-1.16 equiv of acyl chloride was needed in the reaction.     

Stereocontrolled acylation of (η4-cycloheptatriene)iron tricarbonyl

The anion derived by deprotonating (cycloheptatriene)Fe(CO)₃ reacts with acid chlorides to give exo C-7 substitution. The acyl group is readily isomerized to C-5 on treatment with base. The C-7 acylated products can be deprotonated; the resulting anions react at oxygen with acyl chlorides and Me₃SiCl, and at carbon with MeI.     

A comparative study of the reactions of fluorinated oxi- and thiiranes with acyl chlorides

The CoCl₂-catalyzed reactions of fluorinated 1,2-oxi- and thiiranes with acyl chlorides were studied. It was found that a regioselective heterocycle opening reaction resulted in two isomers having normal and abnormal structure in a ratio predetermined by the substituents in both the starting heterocycles and acyl chlorides.     

A versatile access to unsymmetrical and symmetrical α-diketones via organotin reagents

Unsymmetrical α -diketones have been obtained via cross coupling of acyltins with acyl halides under PdCl₂(PPh₃)₂ catalysis while symmetrical α -diketones have been readily obtained via “in situ” formation of acyltins using hexabutylditin and acyl chlorides under similar experimental conditions.     

Reactions of acyl anions generated from acid chlorides and diiodosamarium

Acid chlorides react with SmI₂ to give α-diketones. Various experiments show that the initially formed acyl radical is rapidly transformed into an acyl anion which is thus generated by quite an unusual route.This species acylates acid chlorides, aldehydes and ketones in situ to give α-diketones and α-ketols. There are some limitations to this acyl anion chemistry but the reactions are realized with a good efficiency at room temperature in THF solution.     

A Cs2CO3-mediated simple and selective method for the alkylation and acylation of 3,4-dihydropyrimidin-2(1H)-thiones

Alkyl and acyl derivatives of 3,4-dihydropyrimidin-2(1H)-thiones were synthesized in good to excellent yields in the presence of Cs₂CO₃, a mild base. The method evidences a selective S-alkylation when using acyl chlorides as efficient acylating agents at room temperature on the 2-thioxo-dihydropyrimidone moiety. A possible mechanistic interpretation of the different selectivities in case of alkylation and acylation was done with the help of a geometry optimization process.     

Tributylstannyl Aryl Selenides as Efficient Arylselenating Agents in the Synthesis of Seleno Esters

Tributyltin aryl selenides are convenient and highly efficient arylselenating agents in reactions with acyl chlorides. The activity of acetic anhydride is considerably lower but it can be involved into the arylselenation reaction in the presence of PdCl₂(PPh₃)₂ or boron trifluoride etherate as catalysts.     

Palladium‐Catalyzed Catellani ortho‐Acylation Reaction: An Efficient and Regiospecific Synthesis of Diaryl Ketones

A palladium‐catalyzed, norbornene‐mediated Catellani ortho‐acylation reaction was developed by the use of either acyl chlorides or acid anhydrides as acylation reagents. The addition of more than a stoichiometric amount of H₂O is crucial for this transformation when acid chlorides are used, and kinetic studies indicate that the active acylation reagent is possibly an acid anhydride.     

Direct synthesis of fluorinated peroxides. V. The preparation of pentafluorosulfurperoxy esters by reactions of pentafluorosulfur hydroperoxide with acyl fluorides

The reaction of SF₅OOH with acyl fluorides in the presence of NaF has been investigated and found to yield new peroxy esters of the type RC(O)OOSF₅. An alternate method of synthesis using SF₅OOCl and acyl chlorides is discussed and the cesium fluoride catalyzed conversion of two of the esters to RCF(OF)OOSF₅ is described.     

A new method for making acyl fluorides using BrF3

While many carboxylic acids could be converted directly to acyl fluorides by using BrF₃, the reaction with acyl chlorides was found to be of a more general nature and yields better results. Surprisingly, reacting t-butyl esters with bromine trifluoride also resulted in acyl fluorides in reasonable yields. The reactions were completed in a few seconds at 0 °C.     

Regioselective acylation of methyl 2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate

The influence of catalysts, acid chlorides, and solvents on the acylation of methyl 2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate was studied. The use of AlCl₃ allows the regioselective introduction of the acyl group into position 3 to be performed, whereas the acyl group is regioselectively introduced into position 6 of thienopyrrole when SnCl₄ is used.     

A Facile Route to Convert Acetylacetone into Other β-Diketones with Acyl Chlorides Promoted by Samarium Triiodide

Reaction of acetylacetone with acyl chlorides in the presence of SmI₃ gave β-diketones RCOCH₂COCH₃ (I) or RCOCH₂COR (II) in good yields under mild and neutral conditions.     

An Efficient Method for the Synthesis of N-Acylsulfonamides: One-pot Sulfonylation and Acylation of Primary Arylamines under Solvent-Free Conditions

Summary. The preparation of N-acylsulfonamides is described using primary amines, arylsulfonyl chlorides and acyl chlorides. Reaction of primary aryl amines with arylsulfonyl chlorides in the presence of NaHCO₃ produced N-arylsulfonamides, which reacted in situ with benzoyl chloride furnishing the corresponding N-benzoyl-N-arylsulfonamides in 72–96% yields. Accordingly, 4-nitrobenzoyl chloride and 3,5-dinitrobenzoyl chloride were used as acylating agents. All the reactions were carried out under solvent-free conditions at room temperature and the products were isolated after simple work-up in high yields and purity.     

Acylation des β-énaminoesters: Regio et stéréoformation des β-énaminoesters N- ou C-acylés

The reaction of acyl chlorides with cyclic five-membered β-enaminoesters gave exclusively N-acylated products while reaction of acyl chlorides with cyclic seven-membered β-enaminoesters gave only C-acylated products. In the case of cyclic six-membered β-enaminoesters, the reaction of acyl chlorides gave a mixture of N-acylated and C-acylated products.     

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.     

Synthesis Of 2-Acyltetrahydro-β-Carbolines By An Intramolecular α-Amidoalkylation Reaction

2-Acyltetrahydro-β-carbolines 7 have been obtained by cyclization of adducts 5 from imines 3 of tryptamine 1 and aldehydes 2 with acyl chlorides 4 as a result of an intramolecular a-amidoalkylation reaction in the presence of bases as N,N-dimethylaniline or Et₃N.     

Ionic liquid: an efficient and reusable media for seleno- and thioester synthesis promoted by indium

A series of thio and selenoesters were efficiently obtained employing stable diorganyl chalcogenides, acyl chlorides, and In as reducing agent in BMIM·PF₆. Recycling of the ionic liquid was also performed, which was reused three times.     

Palladium‐ and Solvent‐Free Synthesis of Ynones by Copper(I)‐Catalyzed Acylation of Terminal Alkynes with Acyl Chlorides under Aerobic Conditions

Air‐stable Cu^I/cryptand‐22 complex was found to be a highly active catalyst for the solvent‐free cross‐coupling reaction of terminal alkynes with different acyl chlorides in the presence of Et₃N as base to give the corresponding ynones in quantitative yields.     

Cleavage of Se-Se Bond by Sm/cat. CoCl2 System: A Novel Method for the Synthesis of Selenoesters

The Sm/cat. CoCl₂ system promoted diselenides to react with anhydrides or acyl chlorides to afford selenoesters in good yield under mild and neutral conditions.