112135-47-4Relevant articles and documents
Chemistry of N,N-bis(silyloxy)enamines: Part 5 - Interaction with N-trialkylsilylated azoles. Convenient method for the synthesis of α-azolyl-substituted oximes
Lesiv, Alexey V.,Ioffe, Sema L.,Strelenko, Yury A.,Tartakovsky, Vladimir A.
, p. 3489 - 3507 (2002)
Aliphatic nitro compounds can be considered as good precursors of a wide variety of α-azolyl-substituted oximes. The double silylation of convenient aliphatic nitro compounds and the subsequent N,C-coupling of the resulting N,N-bis(silyloxy)enamines 3 with N-silylated azoles 4 lead to the formation of the silylated α-azolylsubstituted oximes 6, which can be smoothly desilylated to give the target α-azolyl-substituted oximes 5. The mechanism of the key step of this process - N,C-coupling - includes the generation of corresponding conjugated nitrosoalkenes 7 (Schemes 4 and 5). The contribution of the chain mechanism in the overall process is considered as well, The studies of the scope and limitations of this reaction, as well as the optimization of its conditions were accomplished. The configuration of the C=N bond in oximes was established by NMR.
Cycloaddition reactions of nitrosoalkenes, azoalkenes and nitrile oxides mediated by hydrotalcite
Lemos, Americo,Lourenco, Joao P.
scheme or table, p. 170 - 182 (2010/08/20)
Mg:Al 3:1 hydrotalcite (Ht), used in catalytic quantities, promotes the generation of nitrosoalkenes, azoalkenes and nitrile oxides. These can be intercepted in situ by heterocycles and olefins in [4+2] and [3+2] cycloaddition reactions, producing dihydro
A new strategy for the stereoselective synthesis of unnatural α-amino acids
Gallos, John K.,Sarli, Vassiliki C.,Massen, Zoe S.,Varvogli, Anastassia C.,Papadoyanni, Constantina Z.,Papaspyrou, Sofia D.,Argyropoulos, Nicolaos G.
, p. 565 - 574 (2007/10/03)
A new method for the synthesis of racemic non-proteinogenic α-amino acids has been developed, which involves (i) hetero-Diels-Alder addition of ethyl 2-nitrosoacrylate to electron rich alkenes such as enol ethers, enamines and allylsilanes, (ii) NaCNBH3 reduction of the CN bond in the oxazines thus generated, the stereochemistry of the products being controlled by epimerisation of the thermodynamically less stable isomer to the more stable one, (iii) protection of the N-H group as N-Boc and (iv) finally, N-O bond cleavage of both free and protected products to give proline or bis-homoserine derivatives, respectively. An example with concomitant reduction of the carboxylate group, resulting in the formation of the respective amino alcohol is reported. Applying this methodology to a homochiral enol ether, the protected parent d-proline was prepared in enantiomerically pure form, whereas the asymmetric synthesis of the respective bis-homoserine was unsuccessful. Graphical Abstract.
