Structure and Intramolecular Lability of N-(Thio)phosphoryl(thio)amides: XIII. Structure of N-Phenyl-N′-(diisopropoxythiphosphoryl)thiourea

Abstract

The structure and intramolecular transformations of N-phenyl-N`-(diisopropoxythiophosphoryl)-thiourea in (CD 3 ) 2 CO solution were studied by 1 H, 13 C, and 31 P NMR spectroscopy. Combined analysis of NMR data and model calculations gave evidence in favor of high conformational and tautomeric flexibility of the thioureas in solution. The Z,E conformation of the amide form with the two N3H bonds cis and trans to the C=S bond was found to be preferred. Isomeric (thio)ureas are characteristically prone to various conformational transformations which have repeatedly investigated by means of NMR spectroscopy [237]. For example, 1,3-disubstituted thioureas can form 4 rotational isomers. ; = o =; S R 1 R 2 9 9 N N ; = o =; S R 1 9 9 N N R 2 ; = o =; S R 2

N-Acylamidophosphinates: Structure, Properties and Complexation Towards Main Group Metal Cations

“…Ligands containing two essentially different complexing moieties such as a chelating fragment and a macrocycle were developed (Scheme 12). aza-18-crown-6; 1,10-diaza-18-crown-6; benzo-15-crown-5 were synthesized ( Table 1, Table 2) [28][29][30][31][32][33][34][35][36][37][38].…”

“…Dynamic 31 P NMR investigations of NAAP solutions in the temperature range of 353-233K allowed to observe phosphorylotropic processes [69]. T h e r e v e r s i b l e rearrangement of imidoyldithiophosphates into Nthioacylamidothiophosphates (Scheme 15, Path III) was established.…”

“…Based on of the concentration dependence of the NMR spectra [69], it was established that the intermolecular hydrogen bonds broke with dilution of benzamides…”

“…Even at room temperature, prototropic processes are observed in CD 3 CN solutions. For benzamide derivatives 42a and 5 0 a the main route is phosphorylamido-phosphimide tautomerism (Scheme 15, Path II), whereas for thioanalogues 3 7 a and 5 2 it is predominantly amidothion-imidoylthiol tautomerism with the thioamide form prevailing (Path I) [69].…”

NMR Spectroscopic Study of Tautomerism in Solution and in the Solid State

“…Signal assignments for each tautomeric form were made from the analysis of the multiplets in 31 P NMR spectra without proton decoupling and comparison of 4 J PNCSH and 2 J PNH values with respective 1 H NMR values [137]. Also, by employing 31 P chemical shifts the prototropic tautomerism of phosphonous bis(1-methylbenzylamides) could be cleared up (Scheme 5.56) [138].…”