New 1,3,5-heterocyclohexanes bearing pendant phosphorus groups. Structure and N→P pnicogen interactions

Abstract

The syntheses of new 5-alkyl-1,3,5-dithiazinanes, 3,5-dialkyl-1,3,5-thiadiazinanes and 1,3,5-trialkyl-1,3,5-triazinanes, bearing pendant N-propyl groups substituted at β position by -OH, -OP(Y)Ph2, and -P(Y)Ph2 (Y = lone pair, O, S and Se) are reported. Structures were established by 1H, 13C, 31P and 77Se NMR, IR, high resolution TOF mass spectrometry and elemental analyses. The N-propyl groups have a stereogenic center at β carbon and their stereochemistry was analysed. Preferred conformations and intramolecular weak interactions were determined by multinuclear and variable temperature NMR experiments and by DFT optimisation geometry calculations. Pnicogen bonds N→P were found in phosphines and their chalcogenides. New compounds are potential ligands for metallic main group compounds.