Efficient one-step synthesis of pyrrolo[3,4-c]quinoline-1,3-dione derivatives by organocatalytic cascade reactions of isatins and β-ketoamides

Abstract

We describe an efficient one-step synthesis of pyrrolo[3,4-c]quinolinedione derivatives using ethylenediamine diacetate (EDDA)-catalyzed cascade reactions of isatins and β-ketoamides. It is the first direct conversion of isatins to pyrrolo[3,4-c]quinolinedione derivatives via C-N bond cleavage and isatin ring expansion. Furthermore, this reaction provides a one-step synthetic route for the production of biologically interesting complex molecules that are generally prepared using multi-step reactions.

β‐Keto Amides: A Jack‐of‐All‐Trades Building Block in Organic Chemistry

“…Xia and Lee [285] disclosed an organocatalyzed cascade synthesis of pyrroloquinoline‐1,3‐dione derivatives 671 , which exhibited important biological and pharmacological activities. By using ethylenediamine diacetate (EDDA) as the cheap catalyst, β ‐keto amides 669 reacted readily with isatins 670 to form 669‐I (Scheme 142).…”

Domino Reaction of Isatins with α‐Oxoketene‐N,S‐acetals: An Efficient Synthesis of Pyrrolo[3,4‐c]quinoline‐1,3‐diones and 2,3‐Dihydro‐1H‐pyrrolo[3,4‐c]quinolin‐1‐ones

“…Reaction of isatins with different push‐pull alkenes for instance enaminones, ketene N , N ‐acetals, and β‐ketoamides gives rise to diverse pyrroloquinolines such as quinoline‐4‐carboxamides, pyrrolo[3,4‐ c ]quinolin‐1‐ones, imidazopyrroloquinolines, and fused acridine/indole pairs [1g,2e,11] . Yet, to the best of our knowledge, the reaction of isatins with α ‐oxoketene‐ N , S ‐acetals has not been explored so far, even if the reaction appears to be highly exigent because of likely competitive reactions.…”

$$\hbox {Re}_{2}\hbox {O}_{7}$$ Re 2 O 7 -catalyzed formal [3 + 2] cycloaddition for diverse naphtho[1,2-b]furan-3-carboxamides and their biological evaluation

“…In particular, there are no reports of a biological study of naphtho [1,2-b]furan-3-carboxamides. Accordingly, as part of an our ongoing study of the synthesis of bio-active heterocycles [20,[37][38][39][40][41][42][43] and the search for novel anti-tyrosinase, antioxidant, and antibacterial agents [20,21,[44][45][46], diverse naphtho[1,2-b]furan-3-carboxamide derivatives were synthesized starting from 1,4-dihydroxy-2-naphthoic acid via methylation, oxidation, followed by Re 2 O 7 -catalyzed cascade formal [3+2] cycloaddition processes. The synthesized naphtho [1,2-b]furan-3-carboxamides were then evaluated for their anti-tyrosinase, antioxidant, and antibacterial activities.…”