287969-72-6Relevant articles and documents
Radical Isomerization and Cycloisomerization Initiated by H? Transfer
Li, Gang,Kuo, Jonathan L.,Han, Arthur,Abuyuan, Janine M.,Young, Lily C.,Norton, Jack R.,Palmer, Joshua H.
, p. 7698 - 7704 (2016)
Under H2 pressure, CoII(dmgBF2)2L2 (L = H2O, THF) generates a low concentration of an H? donor. Transfer of the H? onto an olefin gives a radical that can either (1) transfer an H? back to the metal, generating an isomerized olefin, or (2) add intramolecularly to a double bond, generating a cyclized radical. Transfer of an H? back to the metal from the cyclized radical results in a cycloisomerization. Both outcomes are favored by the low concentration of the cobalt H? donor, whereas hydrogenation and cyclohydrogenation are more likely with other catalysts (when the concentration of the H? donor is high).
Naphthalene-catalysed lithiation of chlorinated nitrogenated aromatic heterocycles and reaction with electrophiles
Gómez, Inmaculada,Alonso, Emma,Ramón, Diego J.,Yus, Miguel
, p. 4043 - 4052 (2007/10/03)
Naphthalene catalysed reductive lithiation of various chloroazines (1, 7, 10, 13) in the presence of different electrophiles yields, after hydrolysis, the expected functionalised heterocycles with one (2, 8), two (11, 14a-d) and three nitrogen atoms in the ring (14e,f). This methodology allowed us to trap in situ the lithium imine derived from the reaction of 2- pyridyllithium with benzonitrile, by reaction with a Grignard reagent in the presence of titanium alkoxides. 2,4-Dimethoxypyrimidines (14a,c,d) are demethylated under acidic conditions to give the corresponding uracil derivatives 16. (C) 2000 Elsevier Science Ltd.
