252930-65-7Relevant academic research and scientific papers
Facile amidation of esters with aromatic amines promoted by lanthanide tris (amide) complexes
Li, Zhao,Guo, Chenjun,Chen, Jue,Yao, Yingming,Luo, Yunjie
, (2020/02/04)
The development of catalysts capable of catalyzing amidation of esters with amines to construct amides under mild conditions is of great importance. Compared to aliphatic amines, the direct catalytic amidation of esters with less nucleophilic aromatic amines is rather difficult. Employing simple lanthanide tris (amide) complexes Ln[N (SiMe3)2]3(μ-Cl)Li (THF)3 as the catalysts, it was found a broad range of aromatic amines and esters were efficiently converted into various amides in good yields under mild conditions. A plausible mechanism for this transformation was experimentally supported as starting from an amide exchange reaction between the lanthanide tris (amide) complex and the substrate amine.
Electrophile-induced dearomatizing spirocyclization of N- arylisonicotinamides: A route to spirocyclic piperidines
Arnott, Gareth,Brice, Heloise,Clayden, Jonathan,Blaney, Emma
supporting information; experimental part, p. 3089 - 3092 (2009/05/27)
(Chemical Equation Presented) Treatment of N-arylisonicotinamides with trifluoromethanesulfonic anhydride triggers intramolecular nucleophilic attack of the aryl ring on the 4-position of the pyridinium intermediate. The products are spirocyclic dihydropy
Synthesis of 2-pyridinylbenzoxazole: Mechanism for the intramolecular photosubstitution of the haloarene with the carbonyl oxygen of the amide bond in basic medium
Park, Yong-Tae,Jung, Chang-Hee,Kim, Kwang-Wook,Kim, Ho Sik
, p. 8546 - 8556 (2007/10/03)
2-Pyridinylbenzoxazole derivatives have been synthesized by the intramolecular photosubstitution reaction of N-(2- halophenyl)pyridinecarboxamide (1 and 2) with its amide bond in basic medium. In neutral medium both intramolecular photosubstitution and photoreduction reactions occurred. In the photosubstitution reaction a singlet state of the o-haloarene is involved, whereas in the photoreduction a triplet state of the o-haloarene is involved; oxygen inhibited the photoreduction but not the photosubstitution. The relative rate studies showed that a base accelerates the photosubstitution reaction but decelerates the photoreduction. o- Iodoarenecarboxamide is more reactive than o-bromoarenecarboxamide, which in turn is more reacitive than o-chloroarenecarboxamide. UV-vis absorption change in the presence of a base showed that an imidol and/or imidolate anion is involved in the reaction. Several transient species, such as charge- transfer excited states and a cyclohexadienyl anion radical, have been identified from the photolysis of 1 and 2 in basic medium by laser flash photolysis. In neutral medium dibromide anion radical and a phenyl radical were identified in addition to the above intermediates. On the basis of the photokinetic and laser flash photolysis studies, an intramolecular photosubstitution of N-(o-halophenyl)pyridinecarboxamide with its amide bond occurs via an intramolecular S(N)(ET)Ar* mechanism to afford 2- pyridinylbenzoxazole derivative, and the photoreduction proceeds via a free radical mechanism to give N-phenylpyridinecarboxamide.
