The Reactions of Primary Nitroparaffins with Isocyanates1
01 Oct 1960-Journal of the American Chemical Society (American Chemical Society)-Vol. 82, Iss: 20, pp 5339-5342
About: This article is published in Journal of the American Chemical Society.The article was published on 1960-10-01. It has received 503 citations till now. The article focuses on the topics: Nitroparaffins & Thesaurus (information retrieval).
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TL;DR: In contrast to the very large number of special methods applicable to syntheses in the heterocyclic series, relatively few general methods are available as discussed by the authors, and the 1,3-dipolar addition offers a remarkably wide range of utility in the synthesis of five-membered heterocycles.
Abstract: In contrast to the very large number of special methods applicable to syntheses in the heterocyclic series, relatively few general methods are available. The 1,3-dipolar addition offers a remarkably wide range of utility in the synthesis of five-membered heterocycles. Here the “1,3-dipole”, which can only be represented by zwitterionic octet resonance structures, combines in a cycloaddition with a multiple bond system – the “dipolarophile” – to form an uncharged five-membered ring. Although numerous individual examples of this reaction were known, some even back in the nineteenth century, fruitful development of this synthetic principle has been achieved only in recent years.
2,285 citations
1,661 citations
TL;DR: In der 1.3-Dipol-Addition as mentioned in this paper, ein nur bescheidener Satz an Aufbaumethoden von allgemeiner Verwendungsbreite is gegenuber.
Abstract: Einer sehr grosen Zahl spezieller Synthesewege in die heterocyclische in die Reihe steht ein nur bescheidener Satz an Aufbaumethoden von allgemeiner Verwendbarkeit gegenuber. Eine erstaunliche Anwendungsbreite bei der Synthese funfgliedriger Heterocyclen kommt der 1.3-Dipolaren Addition zu. Dabei vereinigt sich der nur mit zwitterionischen Oktett-Grenzformeln wiederzugebende „1.3-Dipol” mit einem Mehrfachbindungssystem, dem „Dipolarophil”, in einer Cycloaddition zum ladungsfreien funfgliedrigen Ring. Wenngleich die Kenntnis zahlreicher Einzelbeispiele bis ins vorige Jahrhundert zuruckreicht, gelangte das Syntheseprinzip erst in den letzten Jahren zu fruchtbarer Entfaltung.
1,135 citations
TL;DR: A new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins.
Abstract: We synthesized a new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold. Among them, thiourea 1e bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the asymmetric Michael reaction of 1,3-dicarbonyl compounds to nitroolefins. Furthermore, we have developed a new synthetic route for (R)-(-)-baclofen and a chiral quaternary carbon center with high enantioselectivity by Michael reaction. In these reactions, we assumed that a thiourea moiety and an amino group of the catalyst activates a nitroolefin and a 1,3-dicarbonyl compound, respectively, to afford the Michael adduct with high enantio- and diastereoselectivity.
884 citations
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