Metal exchange between an electrogenerated organonickel species and zinc halide: application to an electrochemical, nickel-catalyzed Reformatsky reaction
作者:Annie Conan、Soline Sibille、Jacques Perichon
DOI:10.1021/jo00006a012
日期:1991.3
The mechanism of the electroreductive coupling of alpha-chloro esters or alpha-chloro nitriles with carbonyl compounds by the means of a sacrificial zinc anode and a nickel catalyst was elucidated by electroanalytical techniques. The mechanism involved reduction of a Ni(II) complex to a Ni(0) complex, oxidative addition of the alpha-chloro ester to the Ni(0) complex, and a Zn(II)/Ni(II) exchange, leading to an organozinc Reformatsky reagent. The electrosynthesis of various beta-hydroxy esters, beta-hydroxy nitriles, and 2,3-epoxy esters was successfully achieved under extremely mild conditions.
Lettre; Meiners; Wichmann, Naturwissenschaften, 1946, vol. 33, p. 158
作者:Lettre、Meiners、Wichmann
DOI:——
日期:——
Lettre; Wick, Justus Liebigs Annalen der Chemie, 1957, vol. 603, p. 189,196
作者:Lettre、Wick
DOI:——
日期:——
Synthesis and histamine H2 agonistic activity of arpromidine analogues: replacement of the pheniramine-like moiety by non-heterocyclic groups
Analogues of the potent histamine H-2 agonist arpromidine, characterized by non-heterocyclic groups (phenyl, cyclo-hexyl, alkyl) instead of the pheniramine-like portion, were prepared and tested for their H-2 agonistic and H-1 antagonistic activity in the isolated guinea pig right atrium and ileum, respectively. In the diphenylpropylguanidine series an increase in H-2 agonistic potency resulted from mono- or difluorination at one or both phenyl rings in the meta and/or para position (pD2 less-than-or-equal-to 7.75 vs pD2 = 7.15 for the unsubstituted parent compound). Compounds chlorinated at both phenyl rings were considerably less potent. Highest combined H-2 agonistic/H-1 antagonistic potency was found in the 4-fluorophenyl series. The arpromidine analogue with cyclohexyl and methyl group instead of phenyl and pyridine ring proved to be 30 times more potent than histamine in the atrium. The H-1 antagonistic potency in cyclohexyl compounds was lower than in the diaryl series. Thus, aromatic rings appear not to be required for high H-2 agonistic potency but are useful for combined H-2 agonistic/H-1 antagonistic activity.
THOMAS R. C., J. LABELLED COMPOUNDS AND RADIOPHARM., 1978, 15, 591-597