One-step synthesis of 4-alkyl-3-aryl-2,6-dicyanoanilines and their use in the synthesis of highly functionalized 2,3,5,6,7- and 2,3,4,5,7-substituted indoles

An Efficient and Facile Synthesis of 5‐Amino‐3‐methyl‐7‐aryl‐1,3‐dihydroisobenzofuran‐4,6‐dicarbonitrile Derivatives Under Mild Conditions

“…This study was carried out around the key substrate of 2‐methyltetrahydrofuran‐3‐one. In addition, it was found that malononitrile was often used in this kind of reaction . In the beginning of the research, the reaction conditions were studied in detail (Scheme ).…”

A one-pot procedure for the synthesis of novel pyran-fused dicyanoanilines via a triethylamine/aqueous mediated pseudo four-component reaction

“…Search in the literature shows that the existing methods for the preparation of these structures mainly go through MCR routes, [10][11] because the MCR-based methods are more efficient than their equivalent stepwise processes. [12][13][14] In addition, the fluorescence features of dicyanoanilines make them attractive and as a result continuous efforts are devoted by synthetic chemists in recent years to prepare diverse groups of dicyanoanilines [15][16][17][18][19][20] and more studies are underway. Pyran-4-one 1 is an important six-membered heterocyclic compound which is used in the synthesis of various heterocycles containing the pyran unit, 21 possessing diverse biological features, 22 and being part of the structure of several natural products.…”

Jones–Schmid Indole Synthesis

“…Indeed, the simplicity of this reverse-Madelung cyclization suggests that this indole ring synthesis has been encountered by others well prior to the work of Jones and Schmid. Other examples of this reverse-Madelung indole synthesis are depicted in Table 1 [6][7][8][9][10][11][12][13][14][15][16][17]. The generality of Jones's second method is seen by the mild base conversion of acyl sulfonamides to indoles (equation 4) [2].…”

“…Greuter and Schmid employed stronger basic conditions in their cyclization of amides 3 to indoles 4 (equation 5) [3]. This reverse-Madelung indole construction is applicable to the synthesis of 3-aminoindoles, which entails cyclization onto the appropriate nitrile (Entries 4-11) [11][12][13][14][15][16][17]. Another early example is shown in Entry 1, where the triketone was prepared in situ from the ortho-amino ketone and the bromomethyl diketone [6].…”

“…Exceptionally mild conditions formed the indole. In Entry 10 the minor alternative regioisomer (not shown) is formed in 9% to 23% [16]. This reverse-Madelung indole construction is applicable to the synthesis of 3-aminoindoles, which entails cyclization onto the appropriate nitrile (Entries 4-11) [11][12][13][14][15][16][17].…”