15241-23-3Relevant articles and documents
On the Steric Course of the Reaction of Enamines Derived from Open-Chain Aldehydes and Ketones with Nitro-olefins Yielding 2,3-Disubstituted 4-Nitroketones
Seebach, Dieter,Beck, Albert K.,Golinski, Jerzy,Hay, John N.,Laube, Thomas
, p. 162 - 172 (1985)
The relative configuration of the nitro-ketone 12 obtained by the title reaction has been proved by a Baeyer-Villiger degradation and subsequent reduction to the amino-alcohol (+/-)-(u)-20, the relative configuration of which is identical with a sample prepared from 2-methyl-3-hydroxybutyrate of known configuration (Scheme 1).The stereochemical course of the title reaction is thus as predicted by our topological rule.It is assumed that the other nitro-ketones 13-18 described here are also formed by (lk)-combination of the trigonal centers of the educts (diastereoselectivity > 90percent, see Formulae and Fig. 1).It is not possible to reverse this relative topicity by employing (Z)-instead of (E)-components of the starting materials, due to the reversibility of the primary step of these Michael additions (Schemes 2 and 3, and Fig.2).
Visible light-mediated intermolecular [2 + 2] photocycloaddition of 1-aryl-2-nitroethenes and olefins
Mohr, Lisa-Marie,Bauer, Andreas,Jandl, Christian,Bach, Thorsten
supporting information, p. 7192 - 7203 (2019/08/07)
Despite the importance of cyclobutanes there are not many direct [2 + 2] photocycloaddition reactions which can be performed with visible light in the absence of a catalyst. A notable exception is the reaction of 1-aryl-2-nitroethenes and olefins which can be performed at a wavelength of λ = 419 nm or λ = 424 nm in CH2Cl2 as the solvent. In the present study, a total of 15 1-aryl-2-nitroethenes were found to undergo a [2 + 2] photocycloaddition with 2,3-dimethyl-2-butene (28-86% yield) and a set of 12 olefins was studied in their photocycloaddition to 1-phenyl-2-nitroethene (37-88% yield). All mechanistic results are in agreement with a triplet reaction pathway and with the intermediacy of a 1,4-diradical.
Synthetic Diversity from a Versatile and Radical Nitrating Reagent
Zhang, Kun,Jelier, Benson,Passera, Alessandro,Jeschke, Gunnar,Katayev, Dmitry
supporting information, p. 12929 - 12939 (2019/09/17)
We leverage the slow liberation of nitrogen dioxide from a newly discovered, inexpensive succinimide-derived reagent to allow for the C?H diversification of alkenes and alkynes. Beyond furnishing a library of aryl β-nitroalkenes, this reagent provides unparalleled access to β-nitrohydrins and β-nitroethers. Detailed mechanistic studies strongly suggest that a mesolytic N?N bond fragmentation liberates a nitryl radical. Using in situ photo-sensitized, electron paramagnetic resonance spectroscopy, we observed direct evidence of a nitryl radical in solution by nitrone spin-trapping. To further exhibit versatility of N-nitrosuccinimide under photoredox conditions, the late-stage diversification of an extensive number of C?H partners to prepare isoxazolines and isoxazoles is presented. This approach allows for the formation of an in situ nitrile oxide from a ketone partner, the presence of which is detected by the formation of the corresponding furoxan when conducted in the absence of a dipolarophile. This 1,3-dipolar cycloaddition with nitrile oxides and alkenes or alkynes proceeds in a single-operational step using a mild, regioselective, and general protocol with broad chemoselectivity.
Direct aziridination of nitroalkenes affording N-alkyl-C-nitroaziridines and the subsequent Lewis acid mediated isomerization to β-nitroenamines
Hao, Feiyue,Asahara, Haruyasu,Nishiwaki, Nagatoshi
supporting information, p. 5442 - 5445 (2017/11/06)
A mild and highly diastereoselective one-pot synthesis of trans-N-alkyl-C-nitroaziridines was achieved by treatment of nitroalkenes with aliphatic amines and N-chlorosuccinimide. Treatment of the obtained aziridines with a Lewis acid resulted in a facile ring opening reaction, accompanied by rearrangement and isomerization into functionalized (Z)-β-nitroenamines.
