Decarboxylative cyanation and azidation of carboxylic acids: An overview (original) (raw)
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Org. Lett. 2017, 19 (9), 2318-2321.
Allyl nitriles were synthesized from the reactions of arylpropiolic acids with azobis(alkylcarbonitriles) (AIBN or ACCN). In the presence of Cu(OAc) 2 as a catalyst and pyridine as the solvent, the (E)-stereoisomer was formed as the major product. This transformation shows good tolerance toward alkoxy, halogen, alcohol, amine, ester, and ketone functional groups. When the reaction was conducted with the sterically bulky amine, ethyldiisopropylamine, in the absence of a copper catalyst, the corresponding (Z)-stereoisomers were formed preferentially.
Using a polymer-supported azide ion in [2+3] cycloaddition reaction of azide ion with nitriles
Journal of Applied Polymer Science, 2011
The [2þ3] cycloaddition between various nitriles and crosslinked poly(4-vinylpyridine) supported azide ion proceeds smoothly in the presence of ammonium bromide or ammonium chloride in N,N-dimethyl formamide, to give the corresponding 5-substituted-1H-tetrazoles in good to high yields. Conventional heating was used to promote reaction. It was found that using nitriles with electron-withdrawing groups result in bout higher yields and lower reaction times. The present procedure offers advantages, such as shorter reaction time, and simple workup. V
ChemInform, 2011
A practical and efficient process has been developed for the synthesis of 1-substituted 4-acyl-1H-1,2,3triazoles using a three-step one-pot synthetic approach. This transformation involves an initial preparation of triisopropylsilyl (TIPS)-protected ynones from acid chlorides and TIPS-acetylene, followed by a AgF-mediated TIPS deprotection and Cu-catalyzed Huisgen cycloaddition. The increased chemical stability of TIPS-protected ynones was an important factor in the high overall product yield.
Chinese Chemical Letters, 2015
Nitriles are well-known compounds due to their huge potential for applications in synthesis of various bioactive molecules [1-3]. They are viable precursors for preparation of a variety of nitrogencontaining functional compounds [4-7]. In addition, nitriles are versatile and important building blocks of dyes, natural products, herbicides, agrochemicals, pharmaceuticals, and various fine chemicals [8-11]. Therefore, developing a simple and flexible method for the preparation of such compounds is still needful. Numerous approaches to the synthesis of nitriles are completely reviewed in literature. Conventionally used methods are the nucleophilic substitution reaction of alkyl halides with metal cyanides [12], dehydration of primary amides [13,14] or aldoximes [15-26] and oxidative transformation of primary alcohols [27-32], aldehydes [33-36], alkyl halides [37-40], primary aliphatic amines [37-42] and primary azides [43,44]. In addition Pd and Cu catalyzed cyanation of aryl halides was established for the synthesis of benzonitriles [45-47]. Furthermore transformation of esters to nitriles was reported [48-50]. Recently a mild 29 ammoxidation method, which directly converts methyl arenes 30 into aromatic nitriles, has been developed by using Pd(OAc) 2 and 31 N-hydroxyphthalimide (NHPI) as the catalysts, and tert-butyl 32 nitrite as the nitrogen source and oxidant [51]. More recently An 33 NBS mediated nitriles synthesis through C5 5C double bond 34 cleavage has been developed [52]. 35 Undoubtedly, uses of expensive and toxic reagents are some 36 disadvantages of reported methods. Herein an efficient and 37 mild method for mentioned conversion using pentylpyridinium 38 tribromide (PPTB) and aqueous ammonium acetate is reported 39 (Scheme 1). To the best of our knowledge, this is the first report 40 of the application of this reagent for the oxidative conversion 41 of benzyl alcohols, benzyl amines, and benzaldehydes to the 42 corresponding nitriles. 43 2. Experimental 44 Chemicals were purchased from Fluka, Merck, and Aldrich 45 chemical companies. Pentylpyridinium tribromide is a non-46 volatile ionic liquid analog of bromine, which play a dual role as 47 solvent and reagent and can be easily prepared from commercially 48 available starting materials [53]. Thin layer chromatography (TLC) 49 was performed on UV-active aluminum-backed plates of silica gel 50 (TLC Silica gel 60 F 254). Flash chromatography was performed using 51 silica gel (60 Å , 230-400 mesh) with reagent grade solvents. NMR Chinese Chemical Letters xxx (2015) xxx-xxx
Nitriles in organic synthesis: The reaction of trichloroacetonitrile with active methylene reagents
Monatshefte Fur Chemie, 1985
The reaction of trichloroacetonitrile with active methylene reagents such as acetylacetone, benzoylacetone, cyanoacetamide and cyanoacethydrazide is reported. A new simple route for the synthesis of polysubstituted phenols, pyrazoles and pyrroles is also described. Es wird über die Reaktionen von Trichloracetonitril mit aktiven Methylen-Reagentien wie Acetylaceton, Benzoylaceton, Cyanacetamid und Cyanacethydrazid berichtet. Ein neuer einfacher Weg für die Synthese polysubstituierter Phenole, Pyrazole und Pyrrole wird beschrieben.