A Synthesis of N-Bridged 5,6-Bicylic Pyridines via A Mild Cyclodehydration Using the Burgess Reagent and Discovery of A Novel Carbamylsulfonylation Reaction
摘要:
Cyclodehydration using the Burgess reagent provided a novel approach toward the synthesis of N-bridged 5,6-bicylic pyridines including pyrolo-, imidazo-, and triazolopyridines under mild and neutral conditions. The methodology tolerates acid-sensitive functional groups. A novel addition product was observed between the resulting pyrrolo- or imidazopyridine and an additional equivalent of the Burgess reagent, producing the corresponding sulfonylcarbamate adduct.
Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
作者:Eloi P Coutant、Vincent Hervin、Glwadys Gagnot、Candice Ford、Racha Baatallah、Yves L Janin
DOI:10.3762/bjoc.14.264
日期:——
We have explored here the scope of the age-old diethyl malonate-based accesses to α-aminoesters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered
The present invention relates to ion channel modulating agents. More particularly, the present invention relates to a particular class of chemical compounds that has proven useful as modulators of SK Ca, IK Ca and BK Ca channels. In further aspects, the present invention relates to the use of these SK/IK/BK channel modulating agents for the manufacture of medicaments, for methods of therapy, and pharmaceutical compositions comprising the SK/IK/BK channel modulating agents. The SK/IK/BK channel modulating agents of the invention are useful for the treatment or alleviation of diseases and conditions associated with the SK/IK/BK channels.
Synthese des 2-Oxymethyl-indolizidin und des 2-(ω-Oxyaethylen)-indolizidin
作者:Karl Winterfeld、Klaus Küllmar
DOI:10.1002/ardp.19582911002
日期:——
Oxidation of diethyl (pyridylmethyl)malonates with manganese(III) acetate, cerium(IV) ammonium nitrate, and iron(III) perchlorate in the presence of alkenes and alkynes
The oxidation of substituted diethyl 2-, 3-, or 4-picolylmalonates (1a-g) by Mn(III) acetate in acetic acid, Ce(IV) ammonium nitrate in methanol or acetic acid, and Fe(III) perchlorate in acetonitrile in the presence of substituted alkenes (2) and alkynes (3) affords substituted tetra- or dihydroquinolines and/or isoquinolines (4-9) in good to excellent yield. The influence of reaction medium on yield and isomer distribution has been investigated. A mechanism involving oxidative deprotonation of malonic esters by high-valent metal salts to malonyl radicals, their addition to olefins, and intramolecular homolytic substitution to protonated or metal-complexed heteroaromatic bases by the resulting substituted carbon radicals is suggested.