Direct Synthesis of Chiral 1,2,3,4-Tetrahydropyrrolo[1,2-<i>a</i>]pyrazines via a Catalytic Asymmetric Intramolecular Aza-Friedel–Crafts Reaction
作者:Yuwei He、Maohui Lin、Zhongmin Li、Xinting Liang、Guilong Li、Jon C. Antilla
DOI:10.1021/ol2018328
日期:2011.9.2
intramolecular aza-Friedel–Craftsreaction of N-aminoethylpyrroles with aldehydes catalyzed by a chiral phosphoric acid represents the first efficient method for the preparation of medicinally interesting chiral 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines with high yields and high enantioselectivities. This strategy has been shown to be quite general toward various aldehydes and pyrrole derivatives.
N-氨基乙基吡咯与手性磷酸催化的醛类的直接不对称分子内氮杂-Friedel-Crafts反应代表了制备具有医学意义的手性1,2,3,4-四氢吡咯并[1,2- a ]的第一种有效方法具有高收率和高对映选择性的吡嗪。对于各种醛和吡咯衍生物,该策略已被证明是非常普遍的。
Integration of aerobic oxidation and intramolecular asymmetric aza-Friedel–Crafts reactions with a chiral bifunctional heterogeneous catalyst
A new class of chiral bifunctional heterogeneous materials composed of Au/Pd nanoparticles and chiral phosphoric acids as active orthogonal catalysts was prepared by utilizing a facile pseudo-suspension co-polymerization method. It was found that this heterogeneouscatalyst was capable of facilitating the sequential aerobic oxidation-asymmetric intramolecular aza-Friedel–Crafts reaction between benzyl
and isatins, followed by a chiral phosphoric acid-catalyzed asymmetricintramolecular Friedel-Crafts reaction, a new class of valuable chiral 3′,4′-dihydro-2′H-spiro[indoline-3,1′-pyrrolo[1,2-a]pyrazin]-2-ones bearing a quaternary carbon stereocenter were successfully synthesized in good to excellent yields and with moderate to good enantioselectivities under mild reaction conditions.
通过N-氨基乙基吡咯和靛红的直接缩合,再通过手性磷酸催化的不对称分子内Friedel-Crafts反应,得到一类新的有价值的手性3',4'-二氢-2'H-螺[二氢吲哚-具有季碳立体中心的3,1'-吡咯并[1,2- a ]吡嗪]-2-酮在温和的反应条件下以良好至优异的收率和中等至良好的对映选择性成功合成。
Perweew; Martinson, Zhurnal Obshchei Khimii, 1959, vol. 29, p. 2922,2925; engl. Ausg. S. 2883, 2885
作者:Perweew、Martinson
DOI:——
日期:——
Organocatalytic Enantioselective Multicomponent Synthesis of Pyrrolopiperazines
The first organocatalytic multicomponent synthesis of enantioenriched pyrrolopiperazines is reported. These biologically relevant fused tricyclic products were obtained under catalytic iminium activation through a reaction sequence involving an enantioselectiveMichaeladditionfollowed by an iminium ion trapping via Pictet–Spengler cyclization (MAPS sequence). Substantial possibilities for variation