N-Bromosuccinimide as a Brominating Agent for the Transformation of N-H (or N-Benzyl) Ketoaziridines into Oxazoles
摘要:
A novel procedure for the direct synthesis of 2,5-diaryloxazoles starting from N-H ketoaziridines is described. The method proceeds via the in situ formation of N-bromoketoaziridines in the presence of N-bromosuccinimide followed by the generation of intermediate azomethine ylides. A plausible mechanism for this transformation is proposed.
通过将AgBF 4和CuCl结合使用,可以将N-(炔丙基)羟胺立体选择性直接转化为顺式-2-酰基丙啶。发现铜盐可促进中间体4-异恶唑啉向2-酰基氮丙啶的转化,并且可以使用此方法制备3-芳基和3-烷基取代的2-酰基氮丙啶。此外,随后通过立体选择性单锅法从中间体2-酰基氮丙啶与马来酰亚胺原位生成的偶氮甲胺碘化物的1,3-偶极环加成反应得到相应的2-酰基吡咯烷核苷,其中包括一个八氢吡咯并[3, 4‐ c ]吡咯骨架。
Lanthanide replacement in organic synthesis: Luche-type reduction of α,β-unsaturated ketones in the presence of calcium triflate
作者:Nina V. Forkel、David A. Henderson、Matthew J. Fuchter
DOI:10.1039/c2gc35619h
日期:——
calcium-mediated regioselective 1,2-reduction of challenging α,β-unsaturated ketones, such as 2-cyclopententone, is reported. The corresponding allylic alcohols are obtained in very good regioselectivities using Ca(OTf)2 and NaBH4. Furthermore, we have shown that our method can stereoselectively reduce aziridinyl ketones.
Synthesis of aziridines by electrochemical oxidative annulation of chalcones with primary amines
作者:Dongwen Zeng、Lijun Gu、Lizhu Zhang、Ganpeng Li、Yonghui He
DOI:10.1016/j.tetlet.2021.153413
日期:2021.12
Synthesis of aziridines by electrochemical oxidative annulation of chalcone 1,3-diphenyl-2-propen-1-one with primary amines has been developed under external oxidant - and base-free conditions. The reaction constitutes a new transformation of chalcones with primary amines to aziridines, providing a complementary, simple, and environmentally friendly approach to the currently available methods. A reaction
in this area. The literature claimed a different behaviour with phenylisothiocyanate. We have shown that the author's assumptions are based on incorrect structure determination of the products. The addition occurs also on the CN double bond of phenylisothiocyanate and the evolution of the primary adduct (i.e. a thioimidazolidone) is explained by the formation of a biradical stabilized through a capto-dative
1,3-Dipolar cycloaddition of azomethine ylides generated from aziridines in supercritical carbon dioxide
作者:Paulo J.S. Gomes、Cláudio M. Nunes、Alberto A.C.C. Pais、Teresa M.V.D. Pinho e Melo、Luis G. Arnaut
DOI:10.1016/j.tetlet.2006.05.179
日期:2006.7
The 1,3-dipolar cycloaddition of azomethineylides with DMAD in supercritical carbon dioxide is reported. The photolysis reaction conditions were optimized with a suitable adjustment of pressure, temperature, irradiation time and co-solvent concentration leading to a more efficient reaction than in neat acetonitrile. Similar results were observed using thermal reaction conditions. Supercritical carbon
α,β-Unsaturated Aminoketones. VIII.<sup>1</sup> Reaction of Primary Amines with 1,3-Diketones and Bromine Derivatives of Benzalacetophenone. Ethylene Imines
作者:Norman H. Cromwell、Robert D. Babson、Charles E. Harris