2731-01-3Relevant articles and documents
Photocatalytic Cascade Radical Cyclization Approach to Bioactive Indoline-Alkaloids over Donor-Acceptor Type Conjugated Microporous Polymer
Ou, Wei,Zhang, Guoqiang,Wu, Jie,Su, Chenliang
, p. 5178 - 5183 (2019/05/24)
Herein, we describe a visible-light-induced radical strategy for the 1,2-formylarylation of N-arylacrylamides via the C-H activation of 1,3-dioxolane using a carbazolic-cyano conjugated microporous polymer (CC-CMP) as a metal-free photocatalyst. This process provides an efficient and mild approach for constructing highly functionalized formyl-substituted oxindoles, which are valuable building blocks that allow rapid access to various important heterocycle-fused and spirocyclic indole alkaloids. Utilizing this strategy, bioactive alkaloids, such as (±)-desoxyeseroline, (±)-esermethole, and (±)-N-Me-coerulescine, have been concisely synthesized in up to 74% overall yield from low-cost acrylamides and 1,3-dioxolane. The overall yields of our approach are much higher than those of conventional multistep methods. Gram-scale syntheses of natural alkaloids have been demonstrated, highlighting the practical utility of this protocol. The use of CC-CMP photocatalysts, which are metal-free, flexible, stable, effective, and reusable, making this strategy appealing to advanced chemical manufacturing.
Pd(0)-Catalyzed Chemoselective Deacylative Alkylations (DaA) of N-Acyl 2-Oxindoles: Total Syntheses of Pyrrolidino[2,3- b]indoline Alkaloids, (±)-Deoxyeseroline, and (±)-Esermethole
Kumar, Nivesh,Gavit, Vipin R.,Maity, Arindam,Bisai, Alakesh
, p. 10709 - 10735 (2018/09/29)
We report an efficient Pd(0)-catalyzed deacylative allylation of N-acyl 3-substituted 2-oxindoles via the coupling of in situ generated nucleophiles (3 and 4) with allyl electrophiles for the synthesis of a variety of 2-oxindoles with C3-quaternary centers. Gratifyingly, this alkylation process is found to be highly chemoselective in nature, where a C-C bond formation is completely predominant over a C-N bond formation. A variety of key intermediates were synthesized utilizing an aforementioned methodology.
Synthesis of C3-Methyl-Substituted Pyrroloindolines and Furoindolines via Cascade Dearomatization of Indole Derivatives with Methyl Iodide
Yi, Ji-Cheng,Liu, Chuan,Dai, Li-Xin,You, Shu-Li
, p. 2975 - 2979 (2017/11/14)
A highly efficient method for constructing C3-methyl-substituted pyrroloindolines and furoindolines via cascade dearomatization reaction of indole derivatives with methyl iodide was developed. This protocol offers a direct approach to a wide range of C3 methyl substituted pyrroloindolines under mild conditions. The utility of this method was further demonstrated in the concise synthesis of (±)-esermethol.