Synthesis of indane-based [n.3.3] propellane derivatives via ring-closing metathesis

Two examples of indene-based [n.3.3]propellane derivatives are described involving selective alkylation, olefin metathesis and catalytic hydrogenation as key steps. Final compounds were analyzed by NMR and HRMS spectral data

Anomalous Behaviour of cis-Bicyclo[3.3.0]octane-3,7-dione and Its Derivatives During Twofold Fischer Indole Cyclization Using Low-Melting Mixtures

We have developed an efficient method for the synthesis of the pentaleno[2,1-b: 5,4-b'] diindole and pentaleno[2,1-b: 5,6-b'] diindole skeletons via twofold Fischer indole cyclization. In this new procedure, cis-bicyclo[3.3.0] octane-3,7-dione on treatment with 1-methyl-1-phenylhydrazine in the presence of a low-melting mixture of L-(+)-tartaric acid and N, N'-dimethylurea at 70 degrees C undergoes a twofold Fischer indole cyclization to deliver the unusual C-s-symmetrical product pentaleno[2,1-b: 5,6-b'] diindole, along with the expected C-2-symmetrical pentaleno[2,1-b: 5,4-b'] diindole product

DESIGN OF AZA-POLYQUINANES VIA FISCHER INDOLE CYCLIZATION UNDER GREEN CONDITIONS

We have demonstrated a simple and an efficient synthetic route for the synthesis of aza-polyquinane derivatives involving Fischer indole cyclization as a key step under low melting mixture conditions

Diversity-oriented approach to spirocycles via ring-closing metathesis

We have demonstrated a simple and an efficient method for the synthesis of spirocycles starting with inexpensive and commercially available carbonyl compounds. Various spirocycles involving spiropropellane derivative have been assembled via ring-closing metathesis with the aid of Grubbs' first generation catalyst. (C) 2014 Elsevier Ltd. All rights reserved

Hybrid macrocycle formation and spiro annulation on cis-syn-cis-tricyclo[6.3.0.0(2,6)]undeca-3,11-dione and its congeners via ring-closing metathesis

We have developed a simple methodology to transform cis-syn-cis-triquinane derivative 2 into the diindole based macrocycle 6 involving Fischer indolization and ring-closing metathesis (RCM). Various spiro-polyquinane derivatives have been assembled via RCM as a key step

Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps

We demonstrate a new synthetic strategy to cyclophanes containing thiophene and indole moieties via Grignard addition, Fischer indolization and ring-closing metathesis as key steps

Design and synthesis of polycyclic indoles under green conditions via Fischer indolization

A simple and useful synthetic route to aza-polyquinane derivatives involving Fischer indolization under green conditions has been demonstrated. Selenium dioxide is found to be useful for oxidizing some of these indole derivatives

Design and synthesis of polycyclic bisindoles via Fischer indolization and ring-closing metathesis as key steps

Several bisindoles have been synthesized starting with a readily available tetracyclic dione via Fischer indolization and ring-closing metathesis as key steps. The Fischer indolization was achieved under deep eutectic reaction conditions using L-tartaric acid and dimethyl urea (30:70). Various indole derivatives synthesized here are C-2-symmetrical in nature. Due to binding ability, most of the C-2-symmetrical indole moieties exhibit inhibitory activities against to HIV-1 protease, Gram-positive bacteria Bacillus subtilis and Micrococcus luteus. These C-2-symmetric new chemical entities play a special role in medicinal chemistry. (C) 2016 Elsevier Ltd. All rights reserved

SYNTHESIS OF PHENANTHROLINE AND INDOLE BASED HYBRID CYCLOPHANE DERIVATIVES VIA RING-CLOSING METATHESIS

Here, we report new phenanthroline-based cyclophane derivatives via Fischer indolization and ring-closing metathesis (RCM) as key steps. Addition of Grignard reagent to 1,10-phenanthroline-2,9-dicarbaldehyde 2 and subsequent autoxidation gave the bis-alkene dione derivative 3. Further, Fischer indolization 3 followed by RCM under mild reaction conditions gave indole and containing hybrid cyclophanes such as 6a and 6b