Über die Darstellung von Monolithiumphosphid und seine Umsetzung zu primären aliphatischen Phosphinen

Abstract

Kreutzkamp 919 -~ Nr. 6/1954] butylat-Liisung gegeben, die a m 3 g (0.13Mol) Natrium und 125ccm n-Butanol bereitet war. Dabei schied sich Kochmlz aus, das abfiltriert wurde. Bei der Fraktionierung wurden 20 g (63% d.Th.) einer farblosen Fliissigkeit vom Sdp.,, 166-167O erhalten, die sich ah Gl y o xal t e t r anb u t y 1a ce t a1 erwiea. C,,H,,O, (318.5) Ber. C 67.88 H 12.03 Gef. C 67.97 H 12.10 2.3-Dimethoxy-1.4-dioxan (XI): 16 g (0.1 Mol) 1.2-Dichlor-1.2-dimethoxy-& t h a n wurden in 50 ccm trocknem Toluol gelost und tropfenweise zu einer heiBen Losung von 6 g (0.26Mol) Natrium in 50ccm Glykol gegeben. AnschlieDend wurde 1 Stde. unter RiicMuB gekocht. Nach dem Erkalten wurde in Wasser eingegoasen, mit Ather ausgeschiittelt, fiber Natriumsulfat getrocknet und daa Losungsmittel abdeatilliert. Bei der Fraktionierung i.Vak. gingen 5 g (33.8% d.Th.) 2.3-Dimethoxy-1.4-dioxan als farbloae Fliissigkeit bei 78-81°/12 Torr iiber. C,,Hlz04 (148.2) Ber. C48.64 H8.16 Gef. C48.51,48.80 H8.16,8.15 Glyoxal-bis-Bthylen-acetal: 16 g (0.1 Mol) 1.2-Dichlor-1.2-dimethoxy-& t h a n -den mit 13g (0.21 Mol) Glykol auf 150° erhitzt, bis kein Chlorwasserstoff mehr abgespalten wurde. Beim Abkiihlen kristallisierten feine, farblose Nadeln aus, die, am Methanol umkristallisiert, unscharf bei 113-129O schmolzen; Ausb. 2.5 g (17.1% d.Th.). Durch fmktionierte Kristallisation &us Methanol konnten wir das eine Isomere des Glyoxal-bis-Bthylen-acetals vom Schmp. 134.5O und daneben das eutektische Ge-

Silylphosphanes: Developments in Phosphorus Chemistry

“…With PH 3 , Li forms LiPH 2 ·4NH 3 in liquid ammonia, but since NH 3 has to be removed prior to any further synthetic steps, the adduct then yields Li 2 PH . LiPH 2 , obtained from PH 3 and LiPh in Et 2 O, additionally contains Li 2 PH and Li 3 P . That is why from this starting reaction a controlled synthesis of pure silylphosphanes is not achievable.…”

Isolable Diaminophosphide Boranes

“…[1] The borane unit in II serves both as ap rotecting and activatinggroup that suppresses on one hand unwanted side reactions like the formation of phosphonium ions, and may on the otherh and facilitatep hosphide formation,f or example, by boosting the PH-acidity of ap hosphine precursor. [2] Typical phosphide reagents carry usuallyc hemically inert alkyls or aryls( Ia/IIa), [3] but the presence of hydrides (Ib,c/ IIb,c) [4] or substituents based on heavierg roup-14 elements (often Me 3 Si, Id [5] )i sa lso not uncommon. Primary,( Ib/IIb) parent( Ic/IIc)a nd silylated phosphides (Id)a re special because their ability to undergoe lectrophilicp ost-functionalization of reactive PÀHa nd PÀSi bondsa fter the initial metathesis step makest hem essentially polyfunctionalb uilding blocks.…”

“…Typical phosphide reagents carry usually chemically inert alkyls or aryls ( Ia / IIa ), [3] but the presence of hydrides ( Ib,c / IIb,c ) [4] or substituents based on heavier group‐14 elements (often Me 3 Si, Id [5] ) is also not uncommon. Primary, ( Ib / IIb ) parent ( Ic / IIc ) and silylated phosphides ( Id ) are special because their ability to undergo electrophilic post‐functionalization of reactive P−H and P−Si bonds after the initial metathesis step makes them essentially polyfunctional building blocks.…”

“…K[1f]: conversion 70 %. 31 P{ 1 H} NMR (C 6 D 6 ): d = 201.6 ppm (q, 1 J PB = 24 Hz); 11 B{ 1 H} NMR (C 6 D 6 ): d = À29.5 ppm (d, 1 J PB = 24 Hz); 1 HNMR ([D 8 ]THF): d = 7.00-6.63 (m, 6H, m,p-C 6 H 3 ), 5.54 (s, 2H,N CH), 2.46 ppm (s, 12 H, CH 3 ); 13 C{ 1 H} NMR ([D 8 ]THF): d = 127.6 (s, o-C 6 H 3 ), 121.9 (s, p-C 6 H 3 ), 127.8 (d,4 J PC = 1Hz, m-C 6 H 3 ), 117.6 (d, 3 J PC = 6Hz, NCH), 19.5 ppm (s, CH 3 ).Isolation of sodium bis(dimethylamino)phosphide boraneNa[1 b]:Asolution of Na[1b]w as prepared as described above from NaHMDS (80 mg, 0.43 mmol) and 2b (49 mg, 0.36 mmol) in THF (2 mL). Storage at À24 8Cp roduced colorless, highly air and moisture sensitive crystals, which were separated by decantation (no yield determined) and characterized by NMR spectroscopy (see Ta ble 2a nd above) and as ingle-crystal X-ray diffraction study.T he high chemical sensitivity precluded obtaining as atisfactory elemental analysis.…”