A Rapid and Highly Efficient Method for the Synthesis of Benzofulvenes via CsOH‐Catalyzed Condensation of Indene and Aldehydes

Abstract

A fast condensation of indene with a wide range of aldehydes catalyzed by cesium hydroxide monohydrate (CsOH·H2O) for the synthesis of benzofulvenes with good to excellent yields was demonstrated. The condensation can be completed within a few minutes under room temperature and air atmosphere without the use of special ligands or phase‐transfer catalysts. In addition, the ratio of indene to aldehydes played an important role in this reaction. The single condensation products 3 can be obtained as main products with a ratio of 1.2:1, whereas the double condensation products 4 can be obtained by changing the ratio to 1:2.2. This protocol provides an efficient, simple and general method for the synthesis of benzofulvenes 3 and double condensation products 4, which are important intermediates in the synthesis of numerous drugs and natural products.

Nanostructured Manganese Oxides within a Ring‐Shaped Polyoxometalate Exhibiting Unusual Oxidation Catalysis

“…To investigate this unusual reaction mechanism, we focused on the first step of oxygenation and considered three possible steps: SET, [21] HAT, [22] and deprotonation steps; [23] thus, the substrate parameters ionization energy (IE), bond dissociation energy (BDE), and p K a , corresponding to each mechanism, were compared with the substrate scope results (Table 1). Typical oxygenations of alkylarenes start from SET or HAT of alkylarenes, and the reactivities were related to IE or BDE [20–22] .…”

Manganese-Catalyzed Synthesis of Quaternary Peroxides: Application in Catalytic Deperoxidation and Rearrangement Reactions

“…Manganese­(III) acetate dihydrate (97%) and TBHP (5.0–6.0 M) in decane solution were purchased from Sigma-Aldrich. Starting materials 1 , 4 , 6 , and 8 were prepared by the reported method. − All the solvents used were of dry grade. The column chromatographic separations were performed over 100–200 mesh size silica gel.…”

“…Data for 9-benzylidene-9 H -fluorene ( 6a ): 1 H NMR (400 MHz, CDCl 3 ): δ 7.82–7.78 (m, 1H), 7.74–7.71 (m, 3H), 7.57 (dd, J = 14.7, 7.7 Hz, 3H), 7.49–7.45 (m, 2H), 7.42–7.29 (m, 4H), (td, J = 7.7, 1.0 Hz, 1H). 13 C­{ 1 H} NMR (100 MHz, CDCl 3 ): δ 141.5, 139.4, 137.2, 136.4, 135.9, 131.9, 131.1, 128.9, 128.6, 127.2, 126.9, 126.8, 125.8, 124.5, 120.4, 120.0, 120.0, 119.8.…”

Maghnite‐H+ Catalytic Synthesis and Characterization of Polyindenes and Oxidized Derivatives

“…Accordingly, various studies have demonstrated that these features of PIns can be improved by blending or forming copolymers with coumarone, vinyl monomers, methylindene, pyrrole, styrenes, ethylene, polyoxomethylene, and others; or composites with Montmorillonite . In both PIns and indene‐based co‐polymers and composites, the different reactivity of atoms at indenyl groups and, therefore, the distinct indenyl coupling routes remarkably affect the indene spatial orientations and/or polymer structures and properties . These indenyl coupling routes depend on the preparation method and reaction conditions, so their study becomes of paramount importance.…”