Y. Litvinov, A. M. Shestopalov
2011
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0
Influential Citations
34
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Journal
Advances in Heterocyclic Chemistry
Abstract
Publisher Summary The class of 2-amino-4H-pyrans has been known for several decades. Most of the 2-amino-4H-pyrans are colorless, pale-yellow, or pale-cream crystals with high melting points. They are readily soluble in aromatic hydrocarbons, alcohols, acetone, acetonitrile, chloroform, DMF, and DMSO, and nearly insoluble in hexane and water. This chapter focuses on the structure, synthesis, chemical properties, and applications of 2-amino-4H-pyrans. It highlights the use of computational studies, X-ray structural analysis, UV spectroscopy, IR spectroscopy, NMR spectroscopy, and mass spectrometry for the analysis of the structure of 2-amino-4H-pyrans and their physicochemical properties. The most widely known 2-amino-4H-pyrans contain a primary amino group. The general synthetic approach involves cyclization of Michael adducts via nucleophilic addition of an enolic oxygen to a nitrile group and subsequent tautomeric shift of the resultant 2-iminopyran to 2-aminopyran. Acyclic intermediates can be generated from appropriate Michael donors and acceptors, such as methylene-active carbonyl compounds and unsaturated nitriles, or from α,β-unsaturated carbonyl compounds and CH-acidic nitriles. The chapter describes the synthesis of non-annulated 2-amino-4H-pyrans 2-amino-4H-pyrans annulated with five to seven-membered carbocycles 2-amino-4H-benzopyrans, heteroannulated 2-amino-4H-pyrans, and spiro-conjugated 2-amino-4H-pyrans. 2-amino-4H-pyrans are used mainly for biological purposes, such as inhibition of smooth muscle cell proliferation, cell growth inhibition, and arterial intimal thickening after balloon angioplasty when administered systematically. Assays of acetyl- and butyrylcholine esterases inhibition, as well as of the modulation of calcium channels and nicotinic receptors have been conducted in vivo. Also among the fused aminopyrans, 2-amino-4H-chromenes draw especial attention due to their broad biological potential.