Differentiation and assignment of vinyl telluride regioisomers by ¹H‐¹²⁵Te gHMBC

Abstract

Complete (1) H, (13) C, and (125) Te NMR spectral data for some vinyl tellurides are described. The (1) H-(125) Te gHMBC experiment was used for the complete chemical shift assignment and structure elucidation of a mixture of regioisomers. The assignment ((125) Te NMR) and coupling constants (J(H,H) ) for all regioisomers are described for the first time.

Effects of α,β-unsaturated lactones on larval survival and gut trypsin as well as oviposition response of Aedes aegypti

“…1) were synthesized and investigated for the in vitro antitumor and antiinflammatory activities with moderate toxicity (Barros et al, 2014;Freitas et al, 2012).…”

Stereoselective synthesis and antitumoral activity of Z-enyne pseudoglycosides

“…The vinyl tellurides 2d and 3d, however, could be easily separated by flash column chromatography and the regioisomeric purity was determined by 1 H NMR and confirmed by 125 Te NMR and gas chromatography. 14 Next, 3,4,6-tri-O-acetyl-D-glucal, 4, 15 was used as a glycosyl donor in a reaction using different alcohols catalyzed by tellurium tetrachloride(IV). The corresponding pseudoglycosides 5 were obtained in good yields and anomeric selectivities.…”

“…Yellow oil; 85% (1.49 g); IR (thin film cm −1 ) 3050, 2952, 1595, 1457, 1421, 1339, 1299, 1253, 1197, 1152, 1060, 929, 838, 671; 1 H NMR (300 MHz, CDCl 3 ) δ 7.33 (d, J = 10.7 Hz, 1H); 7.01 (d, J = 10.7 Hz, 1H), 6.48 (d, J = 2.2 Hz, 2H), 6.39-6.38 (m, 1H), 3.82 (s, 6H), 2.74 (t, J = 7.5 Hz, 2H), 1.84 (qui, J = 7.2 Hz, 2H), 1.43 (sext, J = 7.2 Hz, 2H), 0.98 (t, J = 7.2 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 ) δ 160.3, 140.6, 136.2, 105.8, 104.9, 99.5, 54.9, 33.5, 24.4, 12.9, 8.6; 125 (Z)-(1-(Butyltellanyl)dec-1-en-3-yloxy)triisopropylsilane (2c). 26 Yellow oil; 90% (2.24 g); 1 H NMR (300 MHz, CDCl 3 ) δ 6.62 14 Yellow oil; 89% (1.78 g); 1 H NMR (300 MHz, CDCl 3 ) δ 6.69 (dt, J = 9.9 and 1.5 Hz, 1H), 6.38 (dt, J = 9.9 and 4.8 Hz, 1H), 4.21 (dd, J = 4.8 and 1.5 Hz, 2H), 2.60 (t, J = 7.5 Hz, 2H), 1.75 (qui, J = 7.5 Hz, 2H), 1.37 (sext, J = 7.5 Hz, 2H), 1.20-1.00 (m, 21H), 0.90 (t, J = 7.5 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 ) δ 138.1, 102.1, 65.7, 34.0, 24.9, 17.9, 13.7, 11.9, 7.0; 125 Te NMR (94.6 MHz, CDCl 3 ) δ 298.6.…”

Hydrotelluration of acetylenic esters: structural characterization of stereoisomers of methyl/ethyl β-(aryltelluro)acrylates

“…In the case of the former, though the regioselectivity of the reaction is reported to favour the 1,2-addition, both the regioisomers have been characterized recently by NMR spectroscopy. 4 On the other hand, hydrotelluration of tertiary propargyl amines was found to be highly regio-and stereospecic to afford (Z)-b-(organotelluro) allylic amines, but that of primary and secondary propargyl amines suffers from considerable loss of regiochemical control. 5 While carbonyl functionalized alkynes were among the rst to be studied under hydrotelluration reactions, 6 there are only a few reports on the hydrotelluration of propargyl aldehydes 7 and esters of propiolic acid [8][9][10][11] as a synthetic route to obtain b-tellurovinylcarbonyl compounds with well dened geometry.…”