Diphenylphosphino benzaldehyde

An NMR tube (5-mm diameter) is charged with 0.207 g (0.713 mmol) of 2-(diphenylphosphino)benzaldehyde.5 Then a solution of 0.152 g (0.776 mmol) of (CO)5MnH in 1.5 mL of toluene is added via syringe. These operations are conveniently performed in a glove box. The tube is fitted with a septum and is vigorously shaken. A small needle connected to a hood vented oil bubbler is inserted into the septum to release the CO that evolves vigorously. After the CO evolution subsides somewhat, the disappearance of the aldehyde 3H NMR doublet (JHP = 5 Hz, 5 10.5) can be monitored. After 10 h, the aldehyde is consumed. 

With the bidentate o-(diphenylphosphino)benzaldehyde (PO) and o-[(diphenylphosphino)benzylidene]aniline (PN) ligands the complexes [ReX(CO)3(PO)] (X is halide, 94) and [ReX(CO)3(PN)] (X is halide, 95) have been synthesized and characterized, starting from [ReX(CO)5] (X is Br, Cl) [92]. Using the same starting material, complexes of the type/ac-[Re(CO)3(K 3-L) (96) were also prepared, where L is a phosphorus-containing heterotridentate ligand, obtained by condensation of 2-(diphenylphosphino)aniline with several salicylaldehyde derivatives (Scheme 24) [93]. 

Tridentate SB ligands having a NPO donor set, combining hard and soft donor atoms, are prepared either by reacting the appropriate (aminoalkyl)diphenylphosphine with sal16 (20, R = -CH2 (20a), -(CH2)3-, (20b), o-C6H4 (20c)), or by reacting 2-(diphenylphosphino)benzaldehyde... 

The precipitated yellow crystals are filtered from the cold solution, affording 20.0 g (53% overall for reactions 2-4) crude 2-(diphenylphosphino)benzaldehyde (the checker obtained a yield of 55%). The product may be easily recrystallized from CH2C12/CH30H. The most effective purification is accomplished by vacuum sublimation at 125° and 0.005 torr onto a water-cooled probe. 

Reductive aminations of ortho- and r to-(diphenylphosphino)benzaldehydes with N,N -bis(2-pyridyl-2-ethyl)-amine (bpea) or l,4-diisopropyl-l,4,7-triazacyclononane (tacn ) afforded four novel ditopic NsP-donor ligands each... 

An unusual C—C bond-forming reaction has been reported in which the interaction of 2-(diphenylphosphino)benzaldehyde with the technetium(V) species [TcCl4(0)] yields the technetium(IV) species (46). In another unusual reaction, the interaction of chlorine with [Pt(S03)(PPh3)2] gives, among other products, complexes in which the phosphine has been oxidized to phosphine oxide and also the phenyl rings have been chlorinated in the 4-position. 

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