24309-22-6Relevant academic research and scientific papers
Transnitrilation from Dimethylmalononitrile to Aryl Grignard and Lithium Reagents: A Practical Method for Aryl Nitrile Synthesis
Reeves, Jonathan T.,Malapit, Christian A.,Buono, Frederic G.,Sidhu, Kanwar P.,Marsini, Maurice A.,Sader, C. Avery,Fandrick, Keith R.,Busacca, Carl A.,Senanayake, Chris H.
supporting information, p. 9481 - 9488 (2015/08/11)
An electrophilic cyanation of aryl Grignard or lithium reagents, generated in situ from the corresponding aryl bromides or iodides, by a transnitrilation with dimethylmalononitrile (DMMN) was developed. DMMN is a commercially available, bench-stable solid. The transnitrilation with DMMN avoids the use of toxic reagents and transition metals and occurs under mild reaction conditions, even for extremely sterically hindered substrates. The transnitrilation of aryllithium species generated by directed ortho-lithiation enabled a net C-H cyanation. The intermediacy of a Thorpe-type imine adduct in the reaction was supported by isolation of the corresponding ketone from the quenched reaction. Computational studies supported the energetic favorability of retro-Thorpe fragmentation of the imine adduct. (Chemical Equation Presented).
A bio-inspired copper catalyst system for practical catalytic cyanation of aryl bromides
Schareina, Thomas,Zapf, Alexander,Cotte, Alain,Mueller, Nikolaus,Beller, Matthias
experimental part, p. 3351 - 3355 (2009/06/06)
A general and environmentally improved protocol for the cyanation of aryl halides with the nontoxic cyanide source potassium hexacyanoferrate(II) {K 4[Fe(CN)6]} using copper catalysis and a ligand system based on 1-alkyl-1H-imidazoles is presented. The advantages of this system are a wide substrate range, high selectivity, easy handling, and inexpensive reagents.
A state-of-the-art cyanation of aryl bromides: A novel and versatile copper catalyst system inspired by nature
Schareina, Thomas,Zapf, Alexander,Maegerlein, Wolfgang,Mueller, Nikolaus,Beller, Matthias
, p. 6249 - 6254 (2008/02/13)
A general protocol for the cyanation of aryl halides with the nontoxic cyanide source K4[Fe(CN)6] using copper catalysis and a ligand system based on 1-alkylimidazoles is presented. The advantages of this system are the high selectivity, a unique substrate range, easy handling, and inexpensive reagents.
Anodic Cyanation of tert-Butylated Anisoles: Competitive Aromatic Additions and Substitutions
Yoshida, Kunihisa,Takeda, Kazusada,Fueno, Takayuki
, p. 3095 - 3098 (2007/10/02)
The electrooxidation of sevral tert-butylated anisoles has been carried out in ,ethanol containing sodium cyanide at a Pt anode in a divided cell.Two types of reactions occured competitively, aromatic-ring addition and substitution.Increasing the level of tert-butyl substitution raises the relative extent of addition to the aromatic ring.An MO calculation has indicated that the order of orientational preference for substitution of the aromatic hydrogen of alkylanisole cation radicals is explained in terms of the LUMO electron densities calculated for the cation radicals.The effect of structure on the oxidation potential of alkylanisoles has also been studied. para Substitution lowers the oxidation potential while ortho substitution raises the potential.
On the Chemistry of (2,4,6-Tri-tert-butylphenyl)isocyanide
Pakusch, Joachim,Ruechardt, Christoph
, p. 1593 - 1594 (2007/10/02)
The thermal rearrangement of (2,4,6-tri-tert-butylphenyl)isocyanide, available from 1,3,5-tri-tert-butylbenzene in 45percent yield by a four-step synthesis, offers a high-yield access to 2,4,6-tri-tert-butylbenzonitrile and -benzoic acid.The rate of this rearrangement is only slightly retarded by the bulky ortho substituents, confirming the pericyclic transition state proposed earlier. - Key Words: Crowded molecules/ Isocyanide rearrangement/ Steric effects
Mechanism and models for homogeneous copper mediated ligand exchange reactions of the type: CuNu + ArX (*) ArNu + CuX
Couture, Christiane,Paine, Anthony James
, p. 111 - 120 (2007/10/02)
The title reactions are an important class of copper mediated nucleophilic aromatic substitution processes, which constitute a useful tool in the molecular design and synthesis of small molecules.We report the results of extensive investigation of these processes, primarily focussing on cyanodeiodination (ArI + CuCN CuI + ArCN).Among the interesting features of these processes are: (a) an unusual rate equation involving autocatalysis by CuI product; (b) retardation by both excess nucleophile (as KCN) and excess leaving group (as KI), which complete with ArX to complex with CuNu; (c) only cuprous nucleophiles are active (ligand exchanged products from cupric salts arise from prior redox equilibria which form CuNu); (d) the halogen effect is large (kI ca 40 - 100 kBr ca 300 - 5000 kCl) but the Hammett q value is zero; (e) ortho-alkyl groups do not hinder the reaction ( and actually cause mild acceleration by relief of steric strain).Finally, the introduction of an ortho-COO- group accelerates the reaction by a factor of 104 - 105 , but the general features of the accelerated reactions are also the same, again indicating a common mechanism, with entropic acceleration by ortho-carboxylate.Both kinetic and thermodynamic factors were considered in detail, the latter apparently for the first time.Applications to practical syntheses are considered, and novel mechanistic models for these interesting processes are discussed.
