Regioselective Cyanation Research Articles

Palladium Catalyzed Cyanation of Diaryl Sulfoxides.

Aryl nitriles are highly versatile and useful compounds. A palladium-catalyzed cyanation of diaryl sulfoxides using bench-stable Zn(CN)2 as the cyanating reagent has been developed. The reaction proceeded well using Pd(OAc)2 as the catalyst with the inexpensive ligand PCy3 in the presence of t-BuONa. The method has a broad scope of substrates and is scalable. The regioselective cyanation of unsymmetrical diaryl sulfoxides was observed at the side of electron-deficient and more steric hindered aryl groups.

B(C6F5)3-catalyzed regio- and stereoselective cyanation of isatogens and their derivatives

Herein we report the regioselective cyanation of isatogen (3-indolone N-oxide) and its derivatives. The high electrophilicity of isatogen is a key feature for their various chemical transformations, and we describe a new application to use boron catalyst for regio- and stereoselective cyanation at C2 position of isatogen. The combination of B(C6F5)3 and Me3SiCN is optimal, and the C2-cyano adducts are exclusively obtained in up to quantitative yield. In addition, isatogenol that includes a tertiary hydroxyl group at C3 position is also suitable for this cyanation to create consecutive tetra-substituted carbons with high stereoselectivity.

Developing piezochromic luminescent materials via regioselective cyanation of naphthalimide–cyanostilbene derivatives

A novel series of piezochromic luminescent materials are designed and the piezochromic phenomenon is successfully promoted by regioselective cyanation.

Copper-Catalyzed Regioselective Cyanation of Indoles via C-H Bond Activation with α-Aminoacetonitriles

AbstractA metal-free and organic cyanating agent, 2-(diisopropylamino)acetonitrile is disclosed for the regioselective synthesis of cyanated indoles such as 2-cyanoindole and 3-cyanoindole derivatives. This method can tolerate a variety of functional groups and can furnish the corresponding cyanated products in moderate to high yields. Moreover, Cu/PhSiH3 system has been identified for the regioselective cleavage of C–H bonds of indoles by the use of metal-free CN sources via a one-pot sequential iodination/cyanation. This cost effective, homogeneous and metal-free CN source system represents the best reaction efficiency in these methodologies.

A Finding on the Direct Regioselective Cyanation of BODIPY

The first example of direct α-cyanation of a BODIPY core has been achieved on 3-(methoxycarbonyl)ethenyl BODIPY. The structure of α-cyanated BODIPY was confirmed by X-ray analysis. Further cyanation took place on the meso-carbon of BODIPY.

Regioselective Cyanation of Six‐Membered N‐Heteroaromatic Compounds Under Metal‐, Activator‐, Base‐ and Solvent‐Free Conditions

AbstractA regioselective cyanation of heteroaromatic N‐oxides with trimethylsilyl cyanide has been developed to obtain 2‐substituted N‐heteroaromatic nitrile without the requirement of any external activator‐, metal‐, base‐, and solvent. The present protocol is a straightforward, one‐pot heteroaromatic C−H cyanation process, and proceeds smoothly in conventional heating but also under microwave irradiation with shorter reaction times. This approach now allows access to a broad class of quinoline N‐oxides and other heteroarene N‐oxides with high to good yields and can also be scaled up to obtain gram quantities. Further application of this process was observed and utilized in late‐stage cyanation of the anti‐malarial drug quinine as well as transformation of the 2‐cyanoazines to a series of biologically important molecules. Based on the experimental observations, a plausible mechanism has also been proposed highlighting the dual role of trimethylsilyl cyanide as a nitrile source and as an activating agent.magnified image

Cyanohydrin-Mediated Cyanation of Remote Unactivated C(sp3)-H Bonds.

A new approach for generation of alkoxy radical from the O-H bond of cyanohydrin promoted by visible-light photoredox catalysis is reported. The alkoxy radical triggers the successive remote HAT and intramolecular cyano migration, leading to the regioselective cyanation of remote C(sp3)-H bonds. The reaction exhibits a broad functional group tolerance that allows many sensitive groups to remain intact under mild conditions. To demonstrate the utility of method, the ketonitrile products are converted to other synthetically valuable compounds.

Hypervalent Iodine(III)‐Mediated Regioselective Cyanation of Quinoline N‐Oxides with Trimethylsilyl Cyanide

AbstractA regioselective cyanation of quinoline N‐oxides with trimethylsilyl cyanide was developed by using (Diacetoxyiodo) benzene (PIDA) as mediated hypervalent iodine(III) reagent under metal‐free and base‐free reaction conditions to obtain 2‐cyanoquinolines. The efficient PIDA reagent could play the role of an activator of the substrates and an accelerator of N−O bond cleavage. The reaction system featured a wide range of substrate suitability and high yields. The procedure was enlarged gram‐scale to synthesize the tuberculosis (TB) inhibitor. Finally, according to some experimental results, a plausible mechanism for the cyanation reaction is proposed.magnified image

Regio-selective cyanation of (Z)-(1,2-dibromo-2-arylvinyl)triisopropylsilane with suppression of halogen elimination

Highly regio-selective cyanation of vicinal (Z)-dibromoalkenyl silanes was achieved by a vinylic Rosenmund-von Braun reaction, significantly suppressing side-production of alkyne. The alkyne was generated by a halogen elimination side-reaction that is an intrinsic problem in metal-activation of vicinal dihaloalkenes. We have studied to overcome the problem, and finally found the combination of CuCN and O=PPh3 in toluene solvent effectively controlled the production of byproducts. The resultant single isomer has significance in potentially application as a multi-tunable synthetic scaffold.

Directing Group‐Assisted Copper(II)‐Catalyzed ortho‐Carbonylation to Benzamide using 2,2′‐Azobisisobutyronitrile (AIBN)

AbstractAn efficient copper‐catalyzed regioselective C—H bond carbonylation of benzamides has been developed using 2,2′‐azobisisobutyronitrile (AIBN) as traceless cyanating agent. The non‐toxic and readily available AIBN was used for the carbonylative cyclization of benzamides via copper catalysis. The method is also applicable for the regioselective cyanation of furan, benzofuran, thiophene, benzothiophene, and pyrrole carboxamide derivatives.magnified image

Substrate-assisted rhodium-catalyzed C[sbnd]H bond cyanation of 2-arylbenzothiazoles

A mild and efficient substrate-assisted CH bond cyanation of 2-arylbenzothiazoles has been developed using CuCN as cyano-group source. The reaction exhibits broad functional groups tolerance giving the desired products in moderate to excellent yields. Regioselective cyanation was in favor of the less sterically hindered position to those meta-substituted substrate.

ChemInform Abstract: A Pd(II)/Mg‐La Mixed Oxide Catalyst for Cyanation of Aryl C—H Bonds and Tandem Suzuki—Cyanation Reactions.

AbstractA simple and efficient method for the regioselective cyanation of aromatic C—H bonds is presented using a reusable Pd(II)/Mg‐La catalyst in the presence of NH4HCO3 and dimethyl sulfoxide as the ‐CN source.

Synthesis of Silodosin by Copper‐Catalysed C–C Arylation

AbstractThe synthesis of silodosin, an antidysuria drug, has been accomplished starting from commercially available indoline. The synthetic strategy is based on CuI‐catalysed C–C arylation, regioselective cyanation, and diastereoselective reductive amination. The enantiopure compound was obtained by selective crystallisation of a diasteroisomeric mixture.

Copper-Mediated Selective Cyanation of Indoles and 2-Phenylpyridines with Ammonium Iodide and DMF

Copper-mediated regioselective cyanation of indoles and 2-phenylpyridines was developed by using ammonium iodide and DMF as the combined source of a cyano unit under "Pd-free" conditions. Mechanistic studies indicate that the reaction of indoles proceeds through a two-step sequence: electrophilic initial iodination and then cyanation. The cyanation has a broad substrate scope, high functional group tolerance, and excellent regioselectivity.

ChemInform Abstract: Expedient Total Synthesis of Triciribine and Its Prodrugs.

AbstractKey step of the novel synthesis of triciribine (VIa) is the regioselective cyanation of compound (I).

Copper-catalyzed cyanation of heterocycle carbon-hydrogen bonds.

A method for regioselective cyanation of heterocycles has been developed. A number of aromatic heterocycles as well as azulene can be cyanated in reasonable to good yields by using a copper cyanide catalyst and an iodine oxidant.

Regioselective cyanation of pyridine 1-oxides with trimethylsilanecarbonitrile: a modified Reissert-Henze reaction

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRegioselective cyanation of pyridine 1-oxides with trimethylsilanecarbonitrile: a modified Reissert-Henze reactionWilmer K. FifeCite this: J. Org. Chem. 1983, 48, 8, 1375–1377Publication Date (Print):April 1, 1983Publication History Published online1 May 2002Published inissue 1 April 1983https://doi.org/10.1021/jo00156a053RIGHTS & PERMISSIONSArticle Views2765Altmetric-Citations110LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (428 KB) Get e-Alerts Get e-Alerts

Regioselective Cyanation of Pyridine-1-oxides

Regioselective Cyanation of Pyridine-1-oxides