- Cerium (III) chloride mediated nitrile aldol reactions: Enhanced diastereoselectivities using a chiral organocerium complex
-
The addition of anhydrous cerium chloride to nitrile aldol reactions has been found to provide high yields of [β-hydroxynitriles. Also, the aldol reaction of α, β-unsaturated carbonyl compounds with nitrile enolates in the presence of cerium chloride affo
- Xiao, Zejun,Timberlake, Jack W.
-
p. 4211 - 4222
(2007/10/03)
-
- Synthesis and histamine H2 agonistic activity of arpromidine analogues: replacement of the pheniramine-like moiety by non-heterocyclic groups
-
Analogues of the potent histamine H2 agonist arpromidine, characterized by non-hetrocyclic groups (phenyl, cyclohexyl, alkyl) instead of the pheniramine-like portion, were prepared and tested for their H2 agonistic and H1 antagonistic activity in the isolated guiea pig right atrium and ileum, respectively.In the diphenylpropylguanidine series an increase in H2 agonistic potency resulted from mono- or difluorination at one or both phenyl rings in the meta and/or para position (pD2 7.75 vs pD2 = 7.15 for the unsubstituted parent compound).Compounds chlorinated atboth phenyl rings were considerably less potent.Highest combined H2 agonistic/H1 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 H1 antagonistic potency in cyclohexyl compounds was lower than in the diaryl series.Thus, aromatic rings appear not to be required for high H2 agonistic potency but are useful for combined H2 agonistic/H1 antagonistic activity. histamine / H2 receptor / H2 agonist / arpromidine / impromidine / H1 antagonist / antihistamine
- Buschauer, A,Friese-Kimmel A,Baumann, G,Schunack, W
-
p. 321 - 330
(2007/10/02)
-
- Metal Exchange between an Electrogenerated Organonickel Species and Zinc Halide: Application to an Electrochemical, Nickel-Catalyzed Reformatsky Reaction
-
The mechanism of the electroreductive coupling of α-chloro esters or α-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 α-chloro ester to the Ni(0) complex, and a Zn(II)/Ni(II) exchange, leading to an organozinc Reformatsky reagent.The electrosynthesis of various β-hydroxy esters, β-hydroxy nitriles, and 2,3-epoxy esters was successfully achieved under extremely mild conditions.
- Conan, Annie,Sibille, Soline,Perichon, Jacques
-
p. 2018 - 2024
(2007/10/02)
-