One-Step Synthesis of the Tricyclic Core of Martinellic Acid from 2-(Cyanomethyl)-3-oxo-N-arylbutanamides

Abstract

A SnCl4.5H2O-mediated facile and efficient one-step synthesis of the tricyclic core of martinellic acid from readily available 2-(cyanomethyl)-3-oxo-N-arylbutanamides was developed and a mechanism involving consecutive hydrolysis of a cyano group and a double annulation process is proposed.

Iron-Catalyzed Vinylogous Aldol Condensation of Biginelli Products and Its Application toward Pyrido[4,3-d]pyrimidinones

“…In the course of our continuous research on the direct syntheses of heterocyclic compounds from readily available acyclic precursors, − we note that there is a potential vinylogous conjugated system in the Biginelli products (Schemes and ). We hypothesized that the Biginelli products 1 should form the vinylogous conjugated systems A in the presence of a suitable catalyst. − Then, the vinylogous enolate A would attack aldehyde 2 to afford the intermediates B , subsequently leading to the products 3 via dehydration (Scheme ). − In our efforts to develop highly efficient methods for functional group transformations, we found that iron salts are effective, reusable, operationally simple, and environmentally benign catalysts. − As a result, we selected ethyl 6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate 1a (1.0 equiv) and 5-acetyl-6-methyl-4-phenyl-3,4-dihydropyrimidin-2(1 H )-one 1b (1.0 equiv), respectively, to react with 2a in the presence of FeCl 3 ·6H 2 O (10 mol %) in CH 3 CN at reflux (Scheme ).…”

Catalyst-free and highly selective electrophilic mono-fluorination of acetoacetamides: facile and efficient preparation of 2-fluoroacetoacetamides in PEG-400

“…On the basis of our studies on acetoacetamides in recent years, [41][42][43][44][45] we found α-fluorination of β-keto amides is a very important class of reaction. But the intolerable reaction mixture often is annoying to isolate.…”

Dimethyl Sulfoxide Participant Iron-Mediated Cascade Oxidation/α-Formylation Reaction of Substituted 2,3-Dihydropyrroles under Air and Protonic Acid Free Condition

“…During the course of our studies on the transformation of easily accessible acetoacetamide derivatives to highly functionalized N -containing heterocyclic compounds, − we found substituted 2,3-dihydropyrroles can afford γ-amino ketones via a ring-opening reaction . We are also interested in the further functionalization of 2,3-dihydropyrroles, which can be readily prepared in high yield by the reaction of doubly activated cyclopropanes with amines .…”