V. P. Jayashankara

Glycine-Catalyzed Efficient Synthesis of Pyranopyrazoles via One-Pot Multicomponent Reaction

A facile and convenient protocol is developed for the fast (5–20 min) and high-yielding (85–95%) synthesis of fused pyranopyrazoles from ethyl acetoacetate, hydrazine hydrate, an aldehyde, and malononitrile in the presence of nontoxic, simple, and readily available organocatalyst glycine in aqueous medium at 25 °C.

Efficient Synthesis of N,N′‐Disubstituted Ureas/Thioureas Catalyzed by Iodine

Abstract Iodine is an efficient catalyst for the synthesis of symmetrically N,N′‐disubstituted ureas/thioureas by heating respective amines or phenyl hydrazine and urea/thiourea on a preheated hot plate at 90–95°C, under solvent‐free conditions. The yields are excellent, and the reactions go to complete within 5–10 min.

Simple and Efficient Procedure for the One‐Pot Synthesis of β‐Acetamido‐β‐aryl‐propiophenones by Molecular Iodine–Catalyzed Tandem Reaction

Abstract Molecular iodine efficiently catalyzes the four‐component tandem reaction of araldehydes, arylmethyl ketones, acetyl chloride, and acetonitrile to afford the corresponding β‐acetamido‐β‐aryl‐propiophenones. The new protocol gives high yields of the products, and the reactions go to completion within 10–15 min on a hot plate at 80–85°C.

Titanium Dioxide‐Mediated Friedel–Crafts Acylation of Aromatic Compounds in Solvent‐Free Condition under Microwave Irradiation

Friedel–Crafts acylation of different arenes was carried out in the presence of titanium dioxide under microwave irradiation in solvent‐free condition. Activated substrates undergo acylation predominantly at the para‐position. An efficient, simple, selective acylation reaction affords good yield of the products and the catalyst could be easily recovered and recycled.

Aluminum-catalyzed efficient synthesis of anilides by the acylation of aryl amines under ultrasonic conditions

Abstract Substituted aryl amines undergo smooth acylation with different acyl chlorides to give anilides under sonic condition (35 kHz, 25°C) in the presence of catalytic amounts of aluminum metal powder in acetonitrile as solvent. All the reactions go to completion within 4 min and give the products in high yields (85–97%).

Selective reduction of azoarenes into arylamine(s) by aluminium/NH 4Br under sonic conditions

Azoarenes, both symmetrical and unsymmetrical are cleaved into arylamine/s by aluminium metal and ammonium bromide in refluxing methanol with high yields. The rate of the reaction is greatly accelerated by irradiating at 35 kHz in a sonic bath maintained at 25 °C.

LiBr-Catalyzed Simple and Efficient Synthesis of Some Novel Substituted Quinolines via Friedlander Heteroannulation Reaction

Abstract A simple and efficient method has been developed for the condensation of o‐aminoaryl ketones with α‐methylene ketones in the presence of catalytic amounts of LiBr to afford the corresponding fused cyclic quinolines in high yield using the Friedlander heteroannulation reaction. The reaction works at ambient temperature to give the products within 1.5–2 h.

Cu-Mg (24: 76) alloy : an efficient catalyst for Friedel-Crafts acylation of arenes

Friedel–Crafts acylation of different arenes was carried out in the presence of Cu–Mg (24:76) alloy under microwave irradiation and solvent-free conditions. Different substrates undergo acylation predominantly at the para-position. An efficient, simple, selective Friedel–Crafts acylation reaction affords good yields of the products and the catalyst could be easily recovered and recycled.