22687-38-3Relevant academic research and scientific papers
C-H activation with elemental sulfur: Synthesis of cyclic thioureas from formaldehyde aminals and S8
Denk, Michael K.,Gupta, Shilpi,Brownie, John,Tajammul, Sabiha,Lough, Alan J.
, p. 4477 - 4486 (2007/10/03)
The C-H activation of cyclic formaldehyde aminals LCH2 (L = RNCH2CH2CH2-NR and RNCH2CH2-NR, R = Me, Et, iPr, tBu, or Ph) with S8 proceeds at unusually low temperatures (T 2S. The reaction constitutes a new, solvent-free method for the synthesis of thioureas that eliminates the toxic and highly flammable CS2. For R = tBu, the ionic carbenium thiocyanates [LCH]+ SCN- dominate the product spectrum and the respective thioureas are obtained in low yield. The reactivity of the analogous sulfur and oxygen ring systems towards S8 was investigated. 1,3-Dithiolane is cleanly converted into 1,3-dithiolane-2-thione (S8, 14 d, 190°C) and resembles the cyclic formaldehyde aminals in this respect. 1,3-Dioxolane (L = OCH2CH2O) is completely inert towards sulfur even under forceful reaction conditions (190°C, 14 d). The formation of thioureas from aminals was investigated at the CBS-4 and B3LYP/6-31G(d) levels of theory.
CYCLIC ORGANIC DERIVATIVES OF HYPOPHOSPHOROUS ACID
Nifantiev, E. E.,Sorokina, S. F.,Borisenko, A. A.,Zavalishina, A. I.,Vorobjeva, L. A.
, p. 3183 - 3194 (2007/10/02)
2-H-1,3,2-Dioxa-, dithia-, diaza- and oxaazaphosphorinanes have been prepared by reducing corresponding phosphorichloridates; spectral and chemical properties of these compounds have been studied.These compounds were considered as initial members of series when investigating the stereochemistry of heterocycles substituted at the phosphorus.The examination of 1H, 13C and 31P NMR spectra has shown that substitution of hydrogen at the phosphorus by axial halogen, alkyl, alkoxy and amido-groups is accompanied by shielding of 4,6-C atoms and deshielding of 4,6-axial protons; introduction of an axial Me group into γ-position to the P-H fragment causes a 30-40 ppm up-field shift of the resonance of the phosporus nucleus.
