An Efficient Synthesis of 3,4-dihydro-2(1H)-pyrimidinones from Aldehyde Bisulfite Adducts using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

: An efficient one pot multicomponent synthesis of 3,4- dihydropyrimidin-2(1H)-ones has been developed from aldehyde bisulfite adducts, ethyl acetoacetate and urea using recyclable polymer supported sulfonic acid catalyst. This new method provides several advantages over previous synthesis including high product yields, commercially viable, minimal workup operations and sustainable chemical practices.

An Efficient Synthesis of 2-Substituted Quinazolin-4(3H)-ones by Using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

Abstract:: An efficient synthesis of 2-substituted Quinazolin-4(3H)-ones has been developed from isatoic anhydride with various amidoximes by using recyclable polymer supported sulphonic acid catalyst. Excellent functional group compatibil-ity and high yields are the important features of this protocol.

Synthesis of a Fluorescent Solvatochromic Resin Using Suzuki–Miyaura Cross-Coupling and Its Optical Waveguide Spectra to Measure the Solvent Polarity on the Surface

We have established a novel analytical method for solvent polarity on resin surface by combining the synthesis of fluorescent solvatochromic resin with optical waveguide spectrometry. The fluorescent solvatochromic resin was obtained via Suzuki–Miyaura cross-coupling between 4-iodobenzoic acid immobilized on Wang resin and 5-[4-(N,N-dihexylamino)phenyl]-2-thienylboronic acid N-methyl-iminodiacetic acid (MIDA) ester. The optical waveguide spectrometry studies on the resin showed a strong fluorescent solvatochromism in various organic solvents.

Urea as an ammonia surrogate in the Hantzsch’s synthesis of polyhydroquinolines /1,4-dihydropyridines under green reaction conditions

: Synthesis of polyhydroquinolines via Hantzsch’s multicomponent reaction (MCR) involves the use of a hygroscopic and moderately toxic ammonium salt as one of the key reactants. In our effort we have found urea as an effective ammonia surrogate when the MCR was performed in the presence of sulphonic acid functionalized Wang resin (Wang-OSO3H) as a polymeric and recoverable acidic catalyst under green conditions. Urea is relatively less hygroscopic / toxic than the commonly used ammonium salts used in this MCR. The methodology afforded a range of polyhydroquinolines in good yields. Depending on the nature of reaction conditions employed the MCR afforded Biginelli product or 1,4-DHPs when the use of 1,3-diketone was omitted.

Traceless Solid-Phase Synthesis of Ketones via Acid-Labile Enol Ethers: Application in the Synthesis of Natural Products and Derivatives

In solid-phase organic synthesis, Wang resin is traditionally used for the immobilization of acids, alcohols, phenols, and amines. We report the use of Wang resin for the traceless synthesis of ketones via acid-labile enol ethers. We demonstrate the practicality of this synthetic strategy on the solid-phase synthesis of pyrrolidine-2,4-diones, which represent the core structure of several natural products, including tetramic acid. Base-triggered condensation of pyrrolidine-2,4-diones yielded 4-hydroxy-1,1′,2′,5-tetrahydro-2H,5′H-[3,3′-bipyrrole]-2,5′-diones.