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Synthese und Reaktionen von 2‐Pyridylphosphan, 2‐C 5 NH 4 ‐PH 2

1990; Wiley; Volume: 123; Issue: 5 Linguagem: Inglês

10.1002/cber.19901230510

0009-2940

G. U. SPIEGEL, O. Stelzer,

Organophosphorus compounds synthesis

Synthesis and Reactions of 2‐Pyridylphosphane, 2C 5 NH 4 ‐PH 2 By reduction of diethyl 2‐pyridylphosphonate ( 1 ) with LiAlH 4 2‐pyridylphosphane ( 2 ) is accessible in ≈︁80% yield. H/D exchange experiments and acid/base exchange reactions between 2 and PhPHLi or Ph 2 PLi show ( 2 ) to be a stronger pH acid than PhPH 2 and Ph 2 PH. Silylation of the lithium phosphides 2‐C 5 NH 4 ‐PRLi (R  H, SiMe 3 ) with Me 3 SiCl affords the corresponding silyl derivatives 2‐C 5 NH 4 ‐PR 2 with CH 3 I or CH 2 Cl 2 yields the mono‐ or bidentate secondary phosphanes 2‐C 5 NH 4 ‐PHMe ( 6 ) and 2‐C 5 NH 4 PHCH 2 PH‐2‐C 5 H 4 N ( 5 ), respectively. On treatment of 2 with CH 3 I or HCl the pyridinium salts [(2‐C 5 NH 4 R)PH 2 ] + X − (R  H, Me; X= Cl, I) are formed. However, coordination of 2 to transition metals in low oxidation states occurs by the phosphorus atom. Addition of the PH bonds in 2 to the activated CC double bonds in acrylic acid esters, mesityl oxide, cinnamnic acid esters, and dimethyl vinylphosphonate leads to chiral P,N hybrid ligands with functional groups in the alkyl side chain.