β,β‐Diacyl‐enamine und ‐enole, 9: Zur Darstellung von Aminomethylenderivaten offenkettiger CH₂‐acider Verbindungen

Abstract

Die Reaktion primlrer und sekundarer aromatischer oder aliphatischer Amine mit Orthocarbonsaureestern und offenkettigen CH,-aciden Verbindungen liefert N-substituierten Aminoalkylidenderivate; die Ausbeuten variieren stark mit der Natur der aktivierenden Gruppen. Die Methode kann fur solche CH2-acide Molekule empfohlen werden, welche durch eine nichtenolisierbare Gruppe (CN, NO, oder PhSO,) aktiviert sind, wahrend niedrige Ausbeute oder keine Umsetzung zu erwarten ist, wenn stark enolisierte methylenaktive Verbindungen eingesetzt werden. CH,-Acide Carbonsluren liefern die Salze 10a -g. fl,jLDiacyl-enamines and -moles, 91) Synthesis of Aminomethylene Derivatives of Open-Chain Active Methylene CompoundsThe reaction of a combination of primary or secondary aromatic or aliphatic amines with orthocarboxylic esters upon a variety of open-chain CH2-acidic molecules gives N-substituted aminoalkylidene derivatives. The method is highly recommended for methylene compounds activated by cyano, nitro, or phenylsulfonyl groups, whereas low yields are obtained, when highly enolized active methylene compounds are used. CH,-Acidic carboxylic acids give salts 10ag.Die hier untersuchte Reaktion zwischen einer CH2-aciden Verbindung, einem Orthoester und einem Amin wurde von Snyder und Jones2) erstmals beschrieben. Sie stellt eine Vereinfachung der schon langer bekannten Umsetzungen CH,-acider Molekiile mit OrthoameisensBureestern Chem.

Silver‐Catalyzed Cross‐Coupling of Isocyanides and Active Methylene Compounds by a Radical Process

“…All the products were obtained with an E configuration, and the stereochemistry was confirmed with the help of an NOE experiment involving 3ak.It is worth mentioning that synthetic methods for enamines like 3,w hich having two different EWGs,are rare. [19] We then turned our attention to investigating the mode of reactivity and effect on the coupling reaction in the case of aliphatic isocyanides (Scheme 2). Gratifyingly,a nu nprecedented C sp3 ÀHcarbamoylation of b-ketoesters with tert-butyl isocyanide (4a)w as discovered, and led to ar ange of tricarbonylmethanes (5a-h)i nm oderate to high yields.…”

Trisubstituted push-pull nitro alkenes

“…Second method B can be considered as an analog to method A for the preparation of 3-amino-substituted reviewed structures. 14,28,[34][35][36][37][38] The products 3-alkylamino-2-nitroacrylic esters used to be prepared by nucleophilic vinylic substitution on 3-alkoxy-2-nitroacrylic esters with adequate N-nucleophile. 28 The paper 31 describing reactions with diverse groups of N-nucleophiles and utilizing "one-pot" reaction pathway B depicted in (Scheme 3), was published in 1963.…”

“…These reactions undergo SNV by a single-step or a multistep addition-elimination mechanism 51 and an inversion of E/Z configuration usually occurs. 52 All types of nucleophiles (C 53,54 , N 29,36,37,55 , S 16,17 ) are known to be utilized in the case of intermolecular reactions. This corresponds to a vast diversity of employed solvents and reaction conditions.…”

“…The second group contains structurally more different products (Scheme 10) that are formed by reaction with usually amino heterocycles as 1,3-binucleophiles. 36,37,62,63 The reaction was studied on trisubstituted nitroalkenes with two different nucleophiles 35,63 (Scheme 11). In both examples, a base was required to form a C-nucleophile in the first SNV step.…”

Silver‐Catalyzed Cross‐Coupling of Isocyanides and Active Methylene Compounds by a Radical Process

“…[19] We then turned our attention to investigating the mode of reactivity and effect on the coupling reaction in the case of aliphatic isocyanides (Scheme 2). Later, the substrate scope of this reaction was extended to other aromatic isocyanides without difficulty.T he electronic properties of the aromatic rings had no influence on either the stereoselectivities or yields of the products 3aa-ak,although use of 2-isocyano-9Hfluorene resulted in as light decrease in the yield of corresponding product (3ak).…”