β-Cyclodextrin Inclusion Complex with Dimethyl[4-hydroxypiperidin-4-yl]Phosphonates as Green Plant Growth Stimulators

Herein we report on the synthesis the synthesis of new dimethyl [1-(benzyl-, 2-phenylethyl-) -4-hydroxypiperidin-4-yl)]phosphonates obtained by reacting 1-(benzyl- or 2-phenylethyl-)piperidone-4 with dimethylphosphite in presence of sodium methylate in hexane. NMR spectroscopy showed that the complexation of β-cyclodextrin (β-CD) (host) with the hydroxyphosphonate (guest) is accompanied by the entry of a hydrophobic aromatic fragment of the substrate molecule into the inner sphere of the host molecule. In addition, the supramolecular interaction of the hydrophilic part of the guest molecule with the outer surface of β-CD is shown. As a result, a 1:1 complex is formed. Dimethyl [1-(benzyl-, 2-phenylethyl-)-4-hydroxypiperidin-4-yl)]phosphonates showed perceptible stimulation of growth and development of stems and/or roots of spring wheat Triticum aestivum Kazakhstanskaya-10, Severyanka and Miras.