- Advantageous Syntheses of Diazo Compounds by Oxidation of Hydrazones with Lead Tetraacetate in Basic Environments
-
Varied sensitive diazo compounds 3 are produced efficiently and safely in 3-6 g quantities by oxidation (eq 1) of hydrazones 1 at -78 deg C with lead tetraacetate (2) in triethylamine/chloroform, N-methylmorpholine/dimethylformamide, tetramethylguanidine (8)/dimethylformamide, and tetramethylguanidine/methylene chloride, respectively, upon use of appropriate workup and handling techniques.New and improved nonhazardous procedures have been developed for preparing and handling hydrazones 1 from aldehydes and ketones in reactions with excess hydrazine.
- Holton, Terrence L.,Shechter, Harold
-
-
Read Online
- Amino- and azidocarbonylation of iodoalkenes
-
Iodoalkenes, available from ketones via their hydrazones, underwent palladium-catalysed azidocarbonylation. Depending on the structure of the acyl azides, consecutive hydrolysis toward corresponding primary amides was observed. ‘Direct’ aminocarbonylation
- Mikle, Gábor,Skoda-F?ldes, Rita,Kollár, László
-
-
- Synthesis of highly substituted cyclobutane fused-ring systems from n-vinyl β-lactams through a one-pot domino process
-
In this contribution, aminocyclobutanes, as well as eight-membered enamide rings, have been made from N-vinyl β-lactams. The eightmembered products have been formed by a [3,3]-sigmatropic rearrangement, whereas the aminocyclobutanes have been derived from a domino [3,3]-rearrangement/6π- electrocyclisation process. The aminocyclobutanes have been obtained in a highly diastereoselective fashion. The cyclobutane ring system tolerates fusion even if adjacent quaternary centres are present. Systems containing up to four fused rings are readily accessible. The reaction profile has been investigated by using Gaussian 03. This study suggests that two reaction pathways for aminocyclobutane formation are possible. In one pathway the [3,3]-sigmatropic rearrangement is the rate-limiting step and in the second pathway the electrocyclisation is rate limiting. Taken together, these reactions should facilitate the construction of fused heterocycles.
- Cheung, Lawrence L. W.,Yudin, Andrei K.
-
supporting information; experimental part
p. 4100 - 4109
(2010/07/05)
-
- ALKENE MIMICS
-
Ac-Phe-Tyr-phosphoSer-Ψ[CH=C]-Pro-Arg-NH2AND Fmoc-bis(pivaloylmethoxy)phosphoSer-Ψ[CH=C]-Pro-2-aminoethyl-(3-indole); and their Phospho-(D)-serine stereoisomers are novel compounds. Ψ refers to a pseudo amide. Such novel compounds advantageousl
- -
-
Page/Page column 19-20
(2010/10/20)
-
- Oxadiazoline ligands for modulating the expression of exogenous genes via an ecdysone receptor complex
-
The present invention relates to non-steroidal ligands for use in nuclear receptor-based inducible gene expression system, and a method to modulate exogenous gene expression in which an ecdysone receptor complex comprising: a DNA binding domain; a ligand binding domain; a transactivation domain; and a ligand is contacted with a DNA construct comprising: the exogenous gene and a response element; wherein the exogenous gene is under the control of the response element and binding of the DNA binding domain to the response element in the presence of the ligand results in activation or suppression of the gene.
- -
-
Page/Page column 27
(2008/06/13)
-
- Serine-cis-proline and serine-trans-proline isosteres: Stereoselective synthesis of (Z)- and (E)-alkene mimics by Still-Wittig and Ireland-Claisen rearrangements
-
Two new amide isosteres of Ser-cis-Pro and Ser-trans-Pro dipeptides were designed and stereo-selectively synthesized to be incorporated into potential inhibitors of the phosphorylation-dependent peptidylprolyl isomerase Pin1, an essential regulator of the
- Wang, Xiaodong J.,Hart, Scott A.,Xu, Bailing,Mason, Matthew D.,Goodell, John R.,Etzkorn, Felicia A.
-
p. 2343 - 2349
(2007/10/03)
-
- Novel efficient synthesis of dibromoalkenes. A first example of catalytic olefination of aliphatic carbonyl compounds
-
A new simple and efficient one pot transformation of various aliphatic carbonyl compounds to the corresponding dibromoalkenes is described. A wide range of hydrazones of aldehydes and ketones. prepared in situ, were easily converted into dibromoalkenes by treatment with carbon tetrabromide in the presence of CuCl. The reaction proceeds under mild conditions to give the target products in good to high yields.
- Korotchenko, Vasily N.,Shastin, Alexey V.,Nenajdenko, Valentine G.,Balenkova, Elizabeth S.
-
p. 1906 - 1908
(2007/10/03)
-
- Pyrazoloquinoline derivatives
-
Compound of formula: ψψ ψwherein R1, Ry, and R3 are hydrogen, alkyl, cycloalkyl, or phenyl or R1 and Ry taken together may form polymethylene, which may be intervened by one or more of oxygen, sulfur, and/or nitrogen and may have 1 or 2 lower alkyls as substituent; R4 is hydrogen or alkyl; R5 and R6 are hydrogen, alkyl, alkyloxy, or halogen, or taken together may form methylenedioxy. ψThe compounds show agonist, antagonist, or inverse agonist activities depending on the difference of their structure, whereby these are thought to be effective for antianxiety, antagonist against anesthetic, and antiencephalopathy.ψ
- -
-
-
- Transition Metal Methylene Complexes, XLV. A Simplified Synthetic Method for μ-Alkylidene Complexes Demonstrated for the Preparation of Novel Dimetallaspiranes
-
The organometallic complexes 1a and 1b react at the metal-metal double bond with the hydrazones 2a - i in the presence of manganese dioxide to give, via the corresponding diazoalkane intermediates, the μ-alkylidene complexes 3a - i and 4a - c, f, i, respe
- Herrmann, Wolfgang A.,Weber, Cornelia,Ziegler, Manfred L.,Pahl, Claudia
-
p. 875 - 894
(2007/10/02)
-