Reaction of 1-methylpyrazoles with aromatic acid chlorides

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, p. 994, July, 1990.     

Palladium-catalyzed reactions of arylboron compounds with carboxylic acid chlorides

Reactions of sodium tetraarylborates and arylboronic acids with acyl chlorides in the presence of palladium salts afford non-symmetrical ketones in high yields under mild conditions.     

Reactions of cyanoacetylhydrazine complexes with salicylaldehyde and consequent metal-promoted reactions

The reactions of salicylaldehyde with a suspension of cyanoacetylhydrazine and/or malonic acid amido-hydrazide complexes in aqueous ethanolic solutions afford novel complexes. The structures of the isolated complexes have been elucidated by conventional physical and chemical measurements. The absence of the cyano group band at 2270 cm⁻¹ in the IR spectra of all complexes, except those of CO(II) and Ni(II) complexes, suggests the promotion of H₂O to the cyano group (CN) forming amido group. Several structures have been proposed in which salicylaldehyde behaves differently toward the cyanoacetylhydrazine complexes. Also, 1-salicylhydrazo-3-imino-3-(o-formyl) phenoxy propionic acid hydrazide is synthesized either by extraction from the isolated solid complexes using disodium ethylene-diaminetetraacetate or during refluxing of Co(II) and/or Fe(II) complexes with salicylaldehyde. This novel compound is confirmed by elemental analysis, spectra (IR and ¹H NMR) and mass spectra.     

Nickel-catalyzed cross-coupling reactions of benzylic zinc reagents with aromatic bromides, chlorides and tosylates

Benzylic zinc reagents prepared by direct insertion of zinc to benzylic chlorides in the presence of LiCl undergo smooth cross-coupling reactions with aromatic chlorides, bromides and tosylates using Ni(acac)(2) and PPh(3) as a catalyst system.     

Novel Petasis boronic acid-Mannich reactions with tertiary aromatic amines

Tertiary aromatic amines can serve as amine substrates for the Petasis boronic acid-Mannich reaction, providing a practical synthetic route for the CC bond formation of α-(4-N,N-dialkylamino-2-alkyloxyphenyl)carboxylic acids. The scope and limitations of this method have been examined.     

Transition metal promoted reactions: XIV. Novel reductive coupling of thioketals with molybdenum hexacarbonyl

Thioketals of fluorenone, acetophenone, tetralone and indanone were treated with Mo(CO)₆ in chlorobenzene to give the corresponding dimeric olefins.     

Preparation of aryl ketones via Ni-catalyzed Negishi-coupling reactions with acid chlorides

A Ni-catalyst-catalyzed cross-coupling reaction of organozinc reagents with acid chlorides has been successfully developed. Mild reaction conditions were required to complete the coupling reactions affording the corresponding aryl ketones in good to excellent yields.     

Transition metal free large-scale synthesis of aromatic vinyl chlorides from aromatic vinyl carboxylic acids using bleach

While continuing our research on Hunsdiecker reaction, we came across an interesting application of bleach, sodium hypochlorite (NaOCl) for decarboxylative chlorination reaction. The reaction is easily scaled up to 10?mmol. The reaction has good tolerance towards wide variety of functional groups. The reaction has mild conditions and gave relatively high chemical yield of the desired product.     

Catalytic reactions of formate. 3. Noble metal chlorides as catalyst precursors for formic acid reactions

Summary Noble metal chlorides (RuCl₃·xH₂O, RhCl₃·3H₂O, PdCl₂ and IrCl₃·xH₂O) have been evaluated as catalyst precursors for the decomposition (HCO₂H H₂ + CO₂), dehydration (HCO₂H H₂O + CO) and air oxidation (2HCO₂H + O₂ 2H₂O + 2CO₂) of 88% HCO₂H at 75–80 °C. RhCl₃ under these conditions is an active oxidation catalyst but not an active decomposition catalyst. However, RuCl₃ is an active decomposition catalyst but not an active oxidation catalyst. PdCl₂ exhibits modest but detectable activity for all three formic acid reactions (decomposition, dehydration and oxidation). IrCl₃ is a relatively active catalyst for all three HCO₂H reactions. A comparison of the catalytic activities of the four noble metal chlorides for HCO₂H decomposition under conditions where both the dehydration and air oxidation reactions are suppressed (4.4% aqueous HCO₂H. Ar atmosphere) indicates the relative catalytic activity sequence: Ir Ru > Pd Rh (inactive).Portions of this work were presented at the 204th National Meeting of the American Chemical Society, Washington, DC, August 1992, paper INOR 124 in abstracts. For part 2 of this series see D. E. Linn Jr, R. B. King and A. D. King Jr, J. Molec. Catal., 80, 165 (1993). 0340-4285.     

Reaction of substituted 2- and 4-methylpyrimidines with aromatic carboxylic acid chlorides

The effect of substituants in methylpyrimidines on the reaction of the methyl groups with aromatic carboxylic acid chlorides in the presence of triethylamine was studied. It is shown that, depending on the character of the substituents, the reaction with the acid chlorides takes place at the methyl groups or at the ring nitrogen atoms.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 687–690, May, 1982.     

CO-retentive addition reactions of fluorinated acid chlorides to alkynes

[reaction: see text]. The reaction of perfluorinated acid chlorides with terminal alkynes is efficiently catalyzed by rhodium complexes and proceeds with retention of the CO moiety in the acid chloride to afford (Z)-1-perfluoroacyl-2-chloro-1-alkenes selectively in high yields.     

Microwave-promoted cross-coupling of acid chlorides with arylboronic acids: a convenient method for preparing aromatic ketones

Simple catalytic systems for cross-coupling reactions of acyl chlorides with arylboronic acids under microwave conditions were tested. Microwave irradiation facilitated the reaction course. Mild reaction conditions afford the symmetrical and unsymmetrical aryl ketones in reasonable to high yields within a short time. A wide range of substrates bearing an electron-donating or an electron-withdrawing substituent on aryl ring of acid chloride as well as on boronic acid were examined and high yields of ketones were produced.     

Alginic acid hydrazide and its reactions with aromatic aldehydes

Alginic acid hydrazide was prepared, and its reactions with aromatic aldehydes were studied. The effect of a substituent in the benzene ring of the aldehyde on the number of arylidene groups introduced into the polymer was examined.     

Claisen rearrangements—VII : Novel reactions of the coumarin,tomentin

The structure of tomentin has been confirmed as 5-hydroxy-6,7-dimethoxycoumarin (2), the derived 3,3-dimethylallyl ether giving a para-Claisen rearrangement product. Relief of strain in the corresponding 1,1-dimethylallyl ether has been found to result in a novel regiospecific ortho-Claisen rearrangement occurring on silica at room temperature. The structure 18 of the stable ortho-dienone formed has been confirmed by conversion of the corresponding dehydrodienone (15), obtained from the rearrangement of tomentin 1,1-dimethylpropargyl ether, to alloxanthoxyletin (25).     

钯催化下三正丁基杂环基锡和酰氯及取代芳烃偶联反应的研究

本文研究了在Pd(PPh3)2Cl2(1)催化下的三正丁基-2-呋喃基锡(6a), 三正丁基-2-噻吩基锡(6a), 三正丁基-2-(N-甲基)吡咯基锡(6c)和菊酰氯(5), 肉桂酰氯(7)的交联反应。发现除了三正丁基-2-(N-甲基)吡咯与5的不寻常反应得到2, 5-二取代的吡咯衍生物外, 其余反应皆以70～87%的产率得到交叉偶联产物。本文同时还报道了钯催化下有机锡试剂与取代卤代芳烃反应, 高收率地得到了不对称的杂环基芳烃和双杂环化合物。在合成的交联产物中, 化合物2, 8, 9, 15, 16与17均为新化合物。     

Synthesis and properties of aromatic polyamide-benzoxazoles from trimethylsilyl-substituted 2,4-diaminophenol and aromatic dicarboxylic acid chlorides

Aromatic poly(o-hydroxy amide)s having inherent viscosities of 0.6–2.2 dL/g were readily synthesized by the low-temperature solution polycondensation of N,N′,O-tris(trimethylsilyl)-substituted 2,4-diaminophenol with aromatic dicarboxylic acid chlorides in various organic solvents. The viscosity values were much higher than those of the polymers obtained by a conventional method using parent 2,4-diaminophenol. Subsequent thermal cyclodehydration of the poly(o-hydroxy amide)s at 280°C under vacuum afforded the corresponding aromatic polyamide-benzoxazoles. Most of the poly(o-hydroxy amide)s dissolved readily in amide-type solvents, whereas the polyamide-benzoxazoles were quite insoluble in organic solvents. The polyamide-benzoxazoles, which gave yellow, transparent, and tough films, had glass transition temperatures of 260–300°C and were stable up to 400°C in air.     

Cobalt-catalyzed ortho-arylation of aromatic imines with aryl chlorides

An ortho-arylation reaction of aromatic imines with aryl chlorides has been achieved using a cobalt-N-heterocyclic carbene catalyst in combination with a neopentyl Grignard reagent. The reaction takes place at room temperature to afford biaryl products in moderate to good yields.