Sulfamic acid: an efficient, cost-effective and recyclable solid acid catalyst for the Friedlander quinoline synthesis

RuCl2(dmso)4 Catalyzes the Solvent‐Free Indirect Friedländer Synthesis of Polysubstituted Quinolines from Alcohols

“…1 [33] Yellow oil (0.56 g, 85 %), t r = 20. [33] Phenyl-1,2,3,4-tetrahydroacridine (3j): [36] Pale yellow solid (0.48 g, 92 %), m.p. 136-138°C.…”

Sulfamic acid: An efficient and green catalyst for synthesis of 1,5‐benzodiazepines under solvent‐free conditions

“…In the past 3 years, owing to its prominent physical and chemical property like outstanding stability, nontoxicity, nonvolatility, odorlessness, ready availability, and extremely cheap price, * sulfamic acid (SA) has increasingly attracted much attention as an alternative acidic catalyst in some heterogeneously catalytic reactions like acetalization [25], esterification [26], acetylation of alcohols and phenols [27], nitrile formation [28], tetrahydropyranylation of alcohols [29], transesterification of β-ketoesters [30], acetolysis of cyclic ethers [31], protection of carbonyls [32], Biginelli [33] and Pechmann condensation [34], Bechmann rearrangement [35], imino-Diels-Alder reaction [36], synthesis of quinolines [37], benzoxanthenes [38], bis(indolyl)methanes [39], and so on. However, there is no report in the literature on the utilization of SA in the synthesis of benzodiazepines via the cyclization of o-phenylenediamine and ketones.…”

BF3·OEt2‐Mediated 1,3‐Hydride Shift Followed by 6π Electrocyclization: An Efficient Route for the Synthesis of Pyridopyrimidine, Pyranoquinoline, and Phenanthroline Derivatives

“…A survey of the literature reveals that several methods have been developed for the synthesis of quinolines, [35] pyranoquinolines, [27b,30] and pyridopyrimidines, [28] but this present methodology is simple, facile, and novel for the construction of these derivatives from a 1-aminopenta-1,4-diene fragment and aldehydes.…”