Base-Promoted Synthesis of N-Substituted 1,2,3-Triazoles via Enaminone–Azide Cycloaddition Involving Regitz Diazo Transfer
摘要:
The domino reactions between NH-based secondary enaminones and tosyl azide have been developed for the synthesis of various N-substituted 1,2,3-triazoles by employing t-BuONa as the base promoter. Through a key Regitz diazo-transfer process with tosyl azide, the reactions proceed efficiently at room temperature with good substrate tolerance.
Two complementary cascade cyclization reactions were described, namely KHSO4-promoted [1+2+3] cyclization and TMSCl-promoted four-molecular cascade cyclization for the concise synthesis of highly functionalized spirooxindoles in excellent yields. Between them, the improved TMSCl-promoted cyclization reaction of isatins, N,N-dimethylenaminones and amines was carried out to afford various desired products
Insights into the unexpected chemoselectivity in Brønsted acid catalyzed cyclization of isatins with enaminones: convenient synthesis of pyrrolo[3,4-c]quinolin-1-ones and spirooxindoles
作者:Hui Xu、Bei Zhou、Pan Zhou、Jie Zhou、Yuehai Shen、Fu-Chao Yu、Ling-Ling Lu
DOI:10.1039/c6cc02659a
日期:——
Divergent cascade syntheses constitute a highly attractive and challenging area in synthetic chemistry, and can exhibit unexpected chemoselectivity. Herein, a Bronsted acid-controlled protocol is described for the efficient catalysis of...
Correction: Insights into the unexpected chemoselectivity in Brønsted acid catalyzed cyclization of isatins with enaminones: convenient synthesis of pyrrolo[3,4-c]quinolin-1-ones and spirooxindoles
作者:Hui Xu、Bei Zhou、Pan Zhou、Jie Zhou、Yuehai Shen、Fu-Chao Yu、Ling-Ling Lu
DOI:10.1039/c6cc90308h
日期:——
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Synthesis of Tetrahydro-indolones through Rh(III)-Catalyzed [3 + 2] Annulation of Enaminones with Iodonium Ylides
+ 2] annulation from simple and readily available enaminones and iodonium ylides has been developed. The novel strategy allows for access to a new class of structurally diverse tetrahydro-indolones with high efficiency and a broad substrate scope. In addition, this transformation represents the first example of the selective Rh(III)-catalyzed alkenyl C–H bond functionalization and annulation of enaminones
4-alkylated 1,4-dihydropyridines (1,4-DHPs). By using terminal olefin as the C4 source of the 1,4-DHP skeleton, this synthetic strategy provides a series of 1,4-DHPs through a 1,1-difunctionalization/cyclization process. In this protocol, two C(sp3)−C(sp2) bonds and a C(sp2)−N bond are simultaneously formed, the hydrogen source on the newly formedmethylgroup of the 1,4-DHP skeleton is confirmed and a possible