Synthese und Reaktivität von Phosphor‐Selen‐Ringen

Abstract

Lawesson‐Reagens für Selenfreunde: Phosphor‐Selen‐Ringe und besonders das Woollins‐Reagens [PhPSe2]2 sind wertvolle Reagentien für die Synthese von Heterocyclen und die Insertion von Selen in organische Substrate. Durch den Einbau von Phosphor‐ und Selenatomen sind Produkte mit überraschend vielfältigen Strukturen erhältlich. Die Entwicklung der Chemie von P‐Se‐Ringen umfasst die Synthese einiger interessanter neuer Strukturmotive und ein neues Reagens: [PhPSe2]2 ist in der organischen Chemie als Woollins‐Reagens bekannt.

Naphthalene and Related Systems peri‐Substituted by Group 15 and 16 Elements

“…[126] We have recently investigated the reactivity of the naphthalene dichalcogenoles with 2,4-diphenyl-1,3-diselenadiphosphetane-2,4-diselenide ((PhPSe 2 ) 2 ,Woollins reagent), which is becoming a very useful selenium source in synthetic chemistry. [127,128] Reacting Woollins reagent with 82 a,b and 85 a in refluxing toluene gives heterocycles 102 containing an E-P(Se)-E motif (Scheme 62). [127] Following their synthesis of the six naphthalene dichalcogenoles, Meinwald et al expanded the series of these compounds to include the acenaphthylene analogues 82.…”

Octaselenocyclododecane

“…[10][11][12] We have been engaged in studying the insertion of selenium into a range of molecules using the P-Se heterocycle Woollins reagent (WR in Scheme 1). [13] We [14] and others [15] have prepared some organic and phosphorus-containing examples of larger rings with diselenide linkages but we are not aware of simple systems like the new ring described below. Here we note that reaction of WR with secondary amines in the presence of CH 2 Cl 2 or CH 2 Br 2 proceeds to give, predictably, bis(N,N-dialkyl-P-phenyl)phosphonamidodiselenoates (1, Scheme 1).…”

“…MS [EI + , m/z]: 518 [MÀCH 2 Se 2 ] + , 424 [MÀCH 2 SeSeCH 2 ] + , 346 [MÀCH 2 SeSeCH 2 Se] + , 254 [MÀCH 2 SeSeCH 2 SeSeCH 2 ] + , 172 [CH 2 SeSeCH 2 SeSeCH 2 Se] + , 94 [CH 2 SeSeCH 2 SeSeCH 2 SeSe] + .Solid-state NMR experiments were performed using Bruker Avance III spectrometers at B 0 of 14.1 T ( 1 H and 13 C) and 9.4 T ( 77 Se), corresponding to 1 H and 13 C Larmor frequencies of 600.2, 150.9, and 76.3 MHz, respectively. Experiments were carried out using Bruker 1.3 mm, 2.5 mm, and 4 mm probes for 1 H,13 C, and 77 Se MAS NMR experiments, respectively, with MAS rates of 60 kHz ( 1 H), 12.5 kHz ( 13 C and 77 Se), and 8 kHz ( 77 Se). For 13 C and 77 Se, MAS NMR spectra were obtained using cross-polarization from 1 H, with contact pulse durations of 1 and 15 ms, respectively, and two-pulse phase modulation (TPPM) decoupling during acquisition.…”