A facile and convenient synthesis of acetic nitronic anhydrides from aliphatic nitroalkenes and lithium ketone enolates and the efficient conversion of these anhydrides to 1,4-diketones, alkylpyrroles, diketone monooximes, dihydro-1,2-oxazines, pyrrolidines, 2-hydroxypyrrolidines, and 1-pyrrolines are recorded.
A novel strategy for the synthesis of stereochemically defined 3,4,5-trisubstituted 2-pyrrolidones was developed. The suggested approach involves reductive domino-type recyclization of 3-aminomethyl-substituted isoxazolines as a key stage. The latter are prepared via α-C–H functionalization of readily available isoxazoline-N-oxides.
Insights into the diastereoselective control in the sulfa-Michael addition of thiols to nitroalkenes: stereoelectronic effect in the cyclic chelated transition state
two approximately 1,2-diaxial substituents due to stereoelectroniceffectcontrol. The stereoelectroniceffect in the cyclic chelated transition state was probed and verified by tuning the steric bulkiness of the corresponding substituents. The reaction involving 1-nitrocyclohexene provided perfect support for the proposed diastereoselective control model. The current investigation provided not only
Fe-Catalyzed Sequential C(sp<sup>3</sup>)–H/N–H Annulation of 2-Methylindoles with Ethyl Trifluoropyruvate at Room Temperature: Construction of Pyrrolo[1,2-α]indoles
An efficient and benign iron-catalyzed room-temperature method was developed for direct sequential C(sp3)–H/N–H annulation to construct pyrroloindole scaffolds. This strategy features cheap and readily available raw materials and mild room-temperature reaction conditions and provides a green and practical method for the one-pot rapid synthesis of a wide range of diversely functionalized pyrrolo[1,2-α]indoles
DABCO-promoted synthesis of pyrazoles from tosylhydrazones and nitroalkenes
作者:Meng Tang、Wen Zhang、Yuanfang Kong
DOI:10.1039/c3ob41435c
日期:——
An efficient synthesis of pyrazoles fromtosylhydrazones and nitroalkenes was developed. In comparison with the previously reported 1,3-dipolar cycloaddition reaction of diazo compounds with electron-deficient alkenes or alkynes, this methodology proceeded with a sequential Baylis–Hillman/intramolecular cyclization mechanism and a variety of reversed regioselectivity products were prepared in good