86164-70-7Relevant articles and documents
Design of an Electron-Withdrawing Benzonitrile Ligand for Ni-Catalyzed Cross-Coupling Involving Tertiary Nucleophiles
Edjoc, Racquel K.,Mills, L. Reginald,Rousseaux, Sophie A. L.
supporting information, p. 10422 - 10428 (2021/07/26)
The design of new ligands for cross-coupling is essential for developing new catalytic reactions that access valuable products such as pharmaceuticals. In this report, we exploit the reactivity of nitrile-containing additives in Ni catalysis to design a benzonitrile-containing ligand for cross-coupling involving tertiary nucleophiles. Kinetic and Hammett studies are used to elucidate the role of the optimized ligand, which demonstrate that the benzonitrile moiety acts as an electron-acceptor to promote reductive elimination over β-hydride elimination and stabilize low-valent Ni. With these conditions, a protocol for decyanation-metalation and Ni-catalyzed arylation is conducted, enabling access to quaternary α-arylnitriles from disubstituted malononitriles.
A one-pot electrophilic cyanation–functionalization strategy for the synthesis of disubstituted malononitriles
Mills, L. Reginald,Rousseaux, Sophie A.L.
, p. 4298 - 4306 (2019/05/22)
Malononitriles are valuable synthetic intermediates for many applications, including the synthesis of herbicides and other biologically active molecules, and the synthesis of chiral ligands for asymmetric catalysis. This article describes the development of a procedure for the conversion of primary nitriles to malononitriles using dimethylmalononitrile, a commercial, non-toxic, carbon-bound source of electrophilic cyanide. This procedure avoids the use of toxic cyanide or malononitrile as a starting material. This protocol is further applied to the dicyanation of benzyl Grignard reagents, generated from benzyl bromides, yielding fully functionalized malononitriles from a nitrile-free precursor.
Facile, Regioselective Synthesis of Highly Solvatochromic Thiophene-Spaced N-Alkylpyridinium Dicyanomethanides for Second-Harmonic Generation
Abbotto, Alessandro,Bradamante, Silvia,Facchetti, Antonio,Pagani, Giorgio A.
, p. 5755 - 5765 (2007/10/03)
The facile and clean synthesis of a novel class of highly solvatochromic chromophores 1 is reported. Compounds 1 are push-pull systems containing a negatively charged dicyanomethanide as a donor group and a positively charged N-alkylpyridinium as an acceptor group. The terminal polar functions are spaced by a thiophene-based moiety containing one or two heterocyclic rings and none, one, or two ethylene bridges. Chromophores 1 have been obtained through a general synthetic scheme involving, as the last step, the 100% regioselective alkylation of the precursor bidentate anions 2, where two competing nucleophilic sites, one neutral at the pyridic nitrogen and one anionic at the carbanionic carbon of the dicyanomethanide group, are present. The unprecedented highly regioselective attack of the alkylating agent onto the neutral pyridic nitrogen rather than the highly charged carbanionic carbon has been also confirmed in the case of the intermolecular competition. Multinuclear (13C and 15N) NMR spectroscopy has been used to investigate the structure and the extent of intramolecular charge transfer in 1, which are shown to exist in the ground state as highly charge-separated zwitterionic systems. Experimental results are discussed and compared with semiempirical (PM3) computations. The solvatochromic response of compounds 1, among the highest ever reported in the literature for similar systems, candidates this class of compounds as very attractive active components of nonlinear optical materials.
