2H-Chromenes (2H-1-benzopyran derivatives) display a broad spectrum of biological activities. The 2H-chromene substructure is an important structural motif present in a variety of medicines, natural products, and materials showing unique photophysical properties. Hence, the structural importance of the benzopyran moiety has elicited a great deal of interest in the field of organic synthesis and chemical biology to develop new and improved synthesis of these molecular skeletons. This review gives an up-to-date overview of different catalytic methodologies developed for the synthesis of 2H-chromenes and is structured around the three main approaches applied in catalytic 2H-chromene synthesis: (I) catalysis with (transition) metals, (II) metal-free Bronsted and Lewis acid/base catalysis, which includes examples of nonenantioselective organocatalysis, and (III) enantioselective organo-catalysis. The section in which the metal-catalyzed reactions are discussed describes different ring-closing strategies based ...

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Catalytic Synthesis of 2H-Chromenes

Total Synthesis of the Highly Potent Anti-HIV Natural Product Daurichromenic Acid along with Its Two Chromane Derivatives, Rhododaurichromanic Acids A and B

Benzofuran itself is an oily chemical compound, extracted from coal tar, which is converted into a synthetic resin, used in different industries. Several derivatives of benzofuran occur naturally in some plants and are the scaffold in several natural products. However, most of them are synthesized via different synthetic routes. In this chapter, we try to highlight the recent advances in the synthetic approaches to this important heterocyclic system and wide variety of its derivatives.

Usha Roa

Papers

Claisen rearrangement of aryl propargyl ethers in poly(ethylene glycol)- a remarkable substituent and solvent effect