By employing triethylamine as a catalyst, [3 + 2] coupling‐eliminationcascade of α,α‐dicyanoolefins with quinonemonoimines was realized. The reactions afforded various novelpterocarpenanalogues with generally moderate yields (up to 75%). In addition, a plausible reaction mechanism was proposed.
The Diels–Alder reactions of para-benzoquinone nitrogen-derivatives: an experimental and theoretical study
作者:Marciana P. Uliana、Bruno M. Servilha、Olga Alexopoulos、Kleber T. de Oliveira、Cláudio F. Tormena、Marco A.B. Ferreira、Timothy J. Brocksom
DOI:10.1016/j.tet.2014.07.088
日期:2014.9
An experimental and theoreticalstudy of the comparative reactivity and selectivity of the Diels–Alder reactions of para-benzoquinones and three nitrogen derivatives have been performed. The mono-oximes derivatives do not react under the tested reaction conditions, whereas the tosylated mono-oximes react slowly. However, the mono N-tosyl imines show excellent reactivity, and superior to the parent
Reaction of N-sulfonyl-1,4-benzoquinone imines with enamines
作者:S. A. Konovalova、A. P. Avdeenko、V. V. Pirozhenko、A. L. Yusina、G. V. Palamarchuk、S. V. Shishkina
DOI:10.1134/s1070428017040054
日期:2017.4
4-benzoquinone imine reacted with enamines to give 1,4-addition products and products of their subsequent cyclization, substituted 5-aminobenzofurans and 5-aminoindoles, depending on the solvent nature, electron-withdrawing power of the substituent on the quinone imine nitrogen atom, and enamine structure. The presence of strong electron-withdrawing trifluoromethanesulfonyl group on the quinone imine nitrogen
Highly enantioselective [3+2] coupling of 3‐substituted indoles with quinone monoimines promoted by a chiral phosphoric acid has been reported. A large variety of benzofuroindolines were prepared in moderate to good yields (up to 98 %) with generally excellent enantioselectivities (up to 99 % ee).
An enantioselective arylative dearomatization reaction of β‐naphthols with quinone monoimides has been developed for the first time using a chiralphosphoricacid as the catalyst, the desired enantioenriched cyclohexadienones were prepared with excellent yields and enantioselectivities by a domino Michael addition and aromatization process (up to 99 % yield, up to 98 % ee). This process is operationally