6-(Trifluoromethyl)-2H-pyran-2-ones: Promising CF3-bearing conjugated cyclic diene and electrophilic building-blocks

摘要

This review describes synthetic methods for the preparation of such advanced conjugated cyclic dienes and electrophiles as 6-CF3-2-pyrones (6-(trifluoromethyl)-2H-pyran-2-ones), their versatile chemical properties and use in the syntheses of various CF3-containing cycloadducts, highly functionalized trifluoromethylated aromatic and heteroaromatic compounds. Synthesis of 6-CF3-2-pyrones bearing a substituent (substituents) at position(s) 3, 4 and 5, regio- and stereoselective preparation of trifluoromethylated cycloadducts (and their derivatives) via Diels-Alder reactions (and retro hetero-Diels-Alder reaction) from these pyrones and compounds containing in their molecules a reactive double (triple) bond, as well as reactions with nucleophiles has been presented in the review. Due to the presence of the electron-withdrawing trifluoromethyl group and the diene moiety, 6-CF3-2-pyrones are highly reactive substrates towards both dienophiles and nucleophiles. High regio- and stereoselectivity of the reactions allows the use of these excellent CF3-containing building-blocks for the preparation of various bicyclic, aromatic and heteroaromatic compounds, important starting substrates in biological or medicinal chemistry and related areas. (C) 2015 Elsevier B.V. All rights reserved.