Recent progress in enantioselective synthesis of C3-functionalized oxindoles: rare earth metals take action

Abstract

The enantioselective synthesis of 3-functionalized oxindole derivatives has experienced an explosive development. This minireview introduces the recent application of rare earth (RE) metal complex catalysts in the synthesis of targeted frameworks. The direct addition reactions of 3-substituted oxindoles or isatins are described, together with a discussion of the catalytic mechanism and related transformations to pharmaceuticals.

Chiral N,N′‐Dioxide/Tm(OTf)3 Complex‐Catalyzed Asymmetric Bisvinylogous Mannich Reaction of Silyl Ketene Acetal with Aldimines

“…Compared with Mannich and VMRs, the catalytic asymmetric bisvinylogous Mannich-type reaction is still in its infancy. [12] Our investigation commenced with the reaction between aldimine 1 a and silyl ketene acetal 2 a as a model to optimize the reaction conditions. [11] To the best of our knowledge, only one example was reported by Yin's group, where phosphine/Cu(I) complex was applied as the catalyst to promote the direct asymmetric bisvinylogous Mannich-type reaction of β,γ,δ,ɛ-unsaturated Nacylpyrazoles (Scheme 1c).…”

Radical Changes in Lewis Acid Catalysis: Matching Metal and Substrate

“…The 3,3-disubstituted oxindole motif,i np articular,h as attracted considerable attention, [17][18][19][20][21] as it occurs in av ariety of biologically and pharmacologically active compounds. [22][23][24][25] Most published enantioselective syntheses employ noble metals, [17][18][19][26][27][28][29][30][31] whereas 3d transition-metal-catalyzed [32] as well as organocatalytic [33][34][35][36] methods have been recently introduced.…”

“…Bottom:R adical sequence leading to the oxindoled imer 6 and its moleculars tructure in the solid state (hydrogen atoms omitted for clarity). C(2)-C(21)1 .6097(18) .…”

The Synthesis of New Spirolactones from Substituted Isatins

“…Such developments are of interest not only for the possible total synthesis of therapeutically useful spirooxindoles [6][7][8][9][10][11][12][13][14][15], but also for the preparation of synthetic analogs [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] in order to improve our knowledge in structure-activity relationships [12-14, 31, 32]. So-called butenolide functionalized spirooxindoles 1 provide the most interesting subject for synthetic investigations in view of the large and ever increasing number of the members of this family which have furan-2(5H)-one 2 as a building block (Scheme 1).…”